The great accuracy test: Part 2

by B.B. Pelletier

Part 1

No other single blog report has had the reception this one has! We have had readers awaken to discuss their favorite things and other readers say they are leaving the blog because they don’t want to read the lengthy comments made by enthusiastic readers who have been stimulated about this subject.

We also had a number of readers who failed to understand what this series will attempt to do, so perhaps I had best state it again clearly, so we all know. The purpose of this series is to discover those things a shooter can do to improve accuracy with an airgun. This is a quest to find out what works, as far as improving accuracy is concerned.

Today, I’m conducting an experiment for you to learn if the trick I mentioned yesterday about using reading glasses works for rifles. I selected an Air Venturi Bronco as a test rifle for several good reasons. The first is that it’s accurate. Next, it’s easy to cock. There will be a lot of shots fired in this test, and I need something that’s easy to cock. Yes, it’s a spring-piston rifle and a PCP would be easier to shoot accurately, but that’s not the point. More of you own springers, so using one is easier for a lot more people. You see, I want you to do this test right along with me. That way, we get a lot more results.

I’m shooting off a rest at 25 yards, so the artillery hold comes into play. Even I make mistakes holding a spring rifle from time to time, so I’m shooting 10-shot groups that will give me some leeway for the occasional bad shot.

This is just the start of a lot of testing with this one rifle, and even so, it’s only the beginning of the great accuracy test. Some of you got that from the title, but for the rest of you I imagine this series could run for a long time and many individual reports. There might even be a book in all of it, if enough worthwhile data is uncovered. But I’m getting ahead of myself. Let’s just see how today goes for starters.

Today’s test is simple and goes like this. I want to discover whether wearing reading glasses is beneficial to my accuracy, so I’m going to shoot groups both with and without the glasses. I will shoot several pellets, but because I’m shooting 10-shot groups, there isn’t enough time for me to shoot all the groups I need to. That’s where some of you come in. Read my test and then conduct one of your own. You can use a different rifle, different pellets and even shoot at different distances if you like, though I would recommend that you shoot out to at least 25 yards to get the group separation needed to show significant differences. Try to model your test after mine, so we can all talk about the same thing.

The test
I’m shooting a Bronco with a Beeman peep sight that was used in the report on the Bronco. The first pellet I tried was the 8.4-grain JSB Exact domed pellet.

NOTE:
Remember that my eyes have recently started to change their prescription during the day. I no longer can see the sights like I could a month ago, and the whole purpose of this test is to find a way to correct that.

JSB Exact 8.4-grain domes
I first shot the Bronco without glasses, trying to see the front sight as best I could. The sight was thin and fuzzy, so it was difficult to see the demarcation between the top of the post and the bottom of the bull. The bull was very clear to me. I shot quickly, but I wasn’t rushing.


Ten JSB Exact 8.4-grain domes shot at 25 yards without the aid of reading glasses. As you can see, I’ve lost the ability to see the sights. This group measures 2.135 inches between centers.

Next, I put on the reading glasses and shot another 10 shots with the same pellet. The front sight was razor-sharp, but the bull was dim, as though in a dream. However, I found that if I shifted focus to the bull and back to the front sight, the bull became much more distinct. I could walk the sight post in to it fairly well that way. It’s another technique that I’ll have to learn and get better at, but it’s possible.


Ten shots with the same 8.4-grain JSB Exact pellet, only this time I was wearing the reading glasses. This group measures 2.085 inches between centers. That’s not a big difference from the first group, however, look at the six pellets in one hole. The first group only had two pellets touching and the central cluster was much larger.

From this first set of targets, I would have to say that it looks like the glasses are helping a little. But one set of data is meaningless, so I continued with other pellets.

BSA Wolverines
The BSA Wolverine is an 8.3-grain domed pellets that is very accurate in certain precharged rifles, so I thought it might do well in the Bronco, too. The first group was shot without the glasses.


The BSA Wolverine pellet grouped like this when I shot without glasses. Yes, there are 10 pellets in this group. Four of them are in the larger hole at the edge of the bull. The group measures 2.048 inches between centers.

I shot 10 more Wolverines with the aid of reading glasses. This time, I knew the technique better, but that didn’t make it any easier.


When using reading glasses I got a group of 10 that measured the same size as without glasses, as near as I can measure it. It measures 2.048 inches between centers. There’s a cluster of three pellets in the lower hole. This target caused me to wonder if this technique is worthwhile.

After seeing this target, I started to wonder if the shooting glasses thing was working as I’d hoped. With two sets of targets in hand, it didn’t seem to make much of a difference. However, I pressed on.

RWS R-10 pellets
Next, I tried the RWS R-10 heavy target pellets. These are the heavier rifle pellets that are suitable for the Bronco’s power.


Ten RWS R-10 pellets shot without the aid of reading glasses. Well, you can certainly see that the point of impact changed dramatically and the group got smaller. Obviously, this is a good pellet for this rifle. This group measures 1.158 inches between centers.

Then, I tried the same pellet with the glasses.


With reading glasses, the RWS R-10 heavy match pellets made almost the same size group. This group measures 1.327 inches between centers. It’s larger than the no-glasses group, but only by a small amount.

Conclusions
What can be said about this test, thus far? Well, I was surprised that the results came out as they did. I thought there would have been a big difference between the two sighting methods, but from these three sets of target it doesn’t seem that way. However, now you can do the same test, those who need the reading glasses, anyway, and see what you come up with.

For you people with good eyes, I haven’t left you out. Tomorrow, I’m going to show you the rest of the test, which is something you can all do, as well. I won’t tell you what that is, nor the results I got, but I will say that it’s quite compelling. In fact, it opens up a whole new test for us to do in the future.

133 thoughts on “The great accuracy test: Part 2

  1. In order to analyze an experiment in a statistically meaningful manner, the assumptions about the experiment should be stated, then the technique that is going to be used to analyze the data should be explained. With these basics in place, there is some basis upon which the experiment can be discussed. Without the basics in place it is very difficult to engage in fruitful discussions.

    So although testing if glasses help is an intriguing idea, I don’t believe that enough of an experimental plan has been devised which can serve as a framework upon which the data can be analyzed.

    I really think the first step of any such testing would be to establish a benchmark. Then you must decide how large a difference you are attempting to detect, and at what confidence interval for the difference being tested.

    Regards,
    Herb



    • Isn’t the original several part test of the Bronco with BB behind the sights the benchmark? One shooter , same one gun, now changing only one thing at a time to see if it makes a difference for this one shooter with this gun. Now ,if you do this with your gun you will be able to tell for yourself if any one change will help you achieve better accuracy with your gun. I think that is the purpose of this series, to help us as individuals to understand why we shoot as we do and how we can shoot better. At least, that’s what I get from it so far,Robert.



        • I think that practical is what this exercise is all about. What I think pissed-off Brain and some others is that a lot of the ramblings of the folks on here who understand all those obscure facts about statistics, was that they were not being honest about practical shooting and shooters.They are to caught up in the math and other peoples accomplishments . What matters is if you can make the shot with your gun when it counts. For that ,you will need to establish what you can do with it ,and what if any changes in your cadence or additions to the piece will help or hinder your shooting with that one particular gun.


          • Like I said in my first response to the proposed shooting test(nothing to do with B.B.’s sideline test of reading glasses) is that there will be a mixed bag of results.

            Let’s say that someone chooses a rifle and pellet combo that is working well. It’s their usual pellet of choice for that particular rifle. They still might want to get a little better accuracy than they have.

            Now, what is going to make a significance difference for them? Barrel cleaning? Sorting by weight? Sorting by head size? Lubed or unlubed?

            As an example, if the pellet weight is VERY consistent, then it will probably not make a noticeable difference. What about size? If that is also very consistent then it might not make a noticeable difference either to measure them.

            If the chosen pellet has a lot of variability in both dimension and weight, then there should be some significance when sorting them each way. And probably BOTH ways.

            The shooter may find that the average pellet is too loose or too tight to shoot the best. What to do next? Look for a better pellet? Decide how many rejects you are willing to put up with? Sort them anyway no matter how many rejects turn up? Just shoot them the way they come from the tin and accept the results?

            I think it is going to turn out differently for everyone. Then a thousand urban legends will be spawned. “You have to do this or that with this kind of rifle or that kind of rifle or this or that kind of pellet to make it shoot good”.

            The original intent of the test will be lost in the results …for everyone except the shooters who participated.

            twotalon


            • twotalon,

              Does the artillery hold work differently for everyone? No, it doesn’t. It works the same for all people, as long as it is correctly done.

              That is what we are looking for, here. Other things that, if done in a certain way, will always improve accuracy.

              They shooter, type of gun or pellet used is immaterial to this quest, except that I have suggested that we select a gun that is reasonably accurate and pellets that compliment the rifle. But this is not brand specific.

              B.B.


              • I was not looking at any particular hold at all in my comment. I was talking about the interraction between the rifle and the pellet specifics only.

                twotalon


              • I think that the artillery hold video is excellent. These things become very important when shooting springers. When hunting, I even wear knee pads and padded bicycle gloves as well as carry seat pad. It always seems like there is an uneven knot where I want to sit or rest the rifle. haha


            • A massive WHAT? Too complicated for me.
              I still think it will work out differently for each shooter. Even with a massive data base the best we can come up with is that results can vary between insignificant and massive depending on the the particular rifle/pellet chosen by the individual shooter. An overall trend may show, but when it comes to individuals, it should vary greatly.

              twotalon.


            • Yeah, I agree. I think what most of us are looking for is what causes or what can we do to eliminate or help reduce “flyers”. Total spread just picking out of a tin of not olympic match pellets doesn’t seem to cut it no matter who makes them. Maybe just the frequency is less. And maybe someone who has match competition experience can tell us what it is that makes olympic match pellets, olympic match pellets. I would imagine surely they don’t just order a tin or do they? The test just posted shows a perfect example with the JSB exact 8.4 grains. The six pellet nice group. But the four way out is what we are interested in reducing or eliminating. And I don’t think it is due to eyesight. I can still shoot quite well with iron sights. I just have to aim at the bottom of a larger bull. haha


      • RE: “you will be able to tell for yourself if any one change will help you achieve better accuracy with your gun.”

        How can you tell that?

        – – – – –

        Which is the best pellet in the Bronco?

        What is the 95% confidence interval for the expected group size?

        Using a 95% confidence interval, is shooting with or without glasses is better?

        Using a 95% confidence interval what is the upper limit (or lower limit) for the difference?

        – – – – – – –

        I agree that you should create a benchmark, then test one thing at a time against the bench mark. This will miss factors that interact with each other. But that will still greatly improve the testing techniques that folks use.

        But to just plink and assume that you have proven something is to invoke a bat wing and a tail of a newt.



        • Sorry Herb, I see your point, but many will agree that shooting is as much an art as it is a science of stats.
          Sometimes, no matter what the science says a particular gun will just not work for a particular shooter…maybe the stock doesn’t fit, maybe the sights aren’t at the right height.
          IMO the only way that stats become as valuable as you feel is if the gun is going to be place in a vice and have no intererence from that one huge variable (that can’t be accounted for by stats)…the shooter.
          I find some of your info interesting…but I want to know how a particular gun will work for a guy like Tom (or Mac) who’s skill sets with a gun are somewhat close to mine. So now I know sort of what to expect from a gun/pellet combination such as the one tested.
          The detailed stats that you talk about would be completely useless to me…for the simple reason that perhaps the gun in question doesn’t fit me as well as it does Tom or Mac (or whoever is testing).
          What most are looking for here (again, only my opinion) is a relative benchmark of what they can reasonably expect from the airgun in thier hands…not what it would do after 100’s statistical shots.




        • BB/Herb,
          I would like to think that it doesn’t matter how accurate a pellet brand is, in our Bronco, during this test. It seems to me, as we try different variables, that we should see a difference in results regardless. Is it possible that a pellet can be so bad that it won’t show any result where a more accurate one will? What I mean is, can’t we just take any pellet brand at random, establish a benchmark with it, and do these experiments, ending with a meaningful result?
          -Chuck


        • Well, to me, the pellet to start at with the Bronco would be the JSB exact 8.4 grain. Then sort by weight, size and weight and size and see what happens. That is what I plan to do with my Benjamin Trail and H&N 12.61 hollow points. Eventually, I’ll get to other pellets and rifles. But this is what I have in hand at the present and because this is exactly the sort of thing you see with your Bronco and I see with my Benj.


    • Herb,

      You are missing the point. This isn’t the experiment. This is the start of the design of one experiment. I asked for reader input. We are designing an experiment here. I said that this wasn’t enough data for any kind of conclusion.

      I did use the word “test” and what I did was, in fact a test. But we are nowhere near the formal experiment level yet.

      As for what I was trying to do, I thought I explained it pretty clearly. It takes too long to go through all of that here, so please re-read what I wrote and see if it doesn’t make sense.

      And how about trying this for me? I need reader input, so we can design an experiment with with replicable results.

      B.B.



      • Ok, my crack at “sound” statistical testing.

        (1) Group size is going to be used as the measure of precision. (read accuracy if you want…)

        This isn’t the best measure but you have to start somewhere. If the shooter wants to make the extra effort to measure X-Y displacements for each shot then that would be better.

        (2) The standard number of shots in a group will be 5.

        More shots in a group would be a better estimator. But the more shots in a group, the more sensitive the group is to a flyer (a shot with a statistically abnormally large dispersion). A 5-shot group is somewhat arbitrarily chosen to be the balancing point between being able to have enough shots to make a single group somewhat stable, but also be able to shoot enough groups to get good statistics.

        (3) The distribution of individual group size measurements is not a normal distribution since you can’t have a group size less than 0. However I don’t know of any tables of data for estimating group sizes based on say 3, 4 or 5 measures of group size. The best data that I know of now is the paper by Taylor and Grubbs which only lists data for a “known” group size relative to an individual group size measurement. In other words, the “known” group size is the measured average group size for an infinite number of groups. See:

        http://www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA006586&Location=U2&doc=GetTRDoc.pdf

        (4) Let’s assume that the average of ten 5-shot groups has a normal distribution. (this shouldn’t be too bad…) Assuming that the standard deviation of an individual standard deviation of the individual 5 shot groups is SD, then for ten 5 shot groups the estimator for the standard deviation would be roughly SD/Sqrt(10).

        Here we need to do some hand waving. Let’s assume that the average of ten 5 shots groups yields the “true” group size which is known only to the oracle on high. Basically we are assuming that the error in measurement of the mean is so small compared to error of in measuring an individual group that it is insignificant. Now we can use Tables 1 and 2 from the paper by Taylor and Grubbs. More groups would be better, but there is not any good analysis for using the average of a small number of groups.

        NOTES:
        * The measured standard deviation of the ten 5-shot groups will likely be quite large. If you used the T-test, the 95% confidence interval would likely be wide enough to have a negative number as the lower bound for group size. That of course is ludicrous, and due to the fact that the individual measurements of a 5-shot group size do not have a normal distribution.

        (4) Called shots

        If we make a mistake in shooting, eg we get startled and squeeze a shot off by mistake, then the shot can be “called.” You should call the shot before seeing where the shot lands on the target. The idea isn’t just to reject shots that you don’t like after the fact. If the called shot is so far from the group that its position won’t interfere with group measurement finish the group so that you get 5 shots to measurement. Otherwise, start over with another group.

        “Called” has been used in other ways. The name and definition are semantics. A good glossary would help…

        (5) Flyers – Without knowing the percentage of flyers, it is impossible to guess at what the right number of shots in a group will be. In essence we’ll assume:

        If the shot is normal then the group size is GS(typical), but if the shot is abnormal then the group size is GS(abnormal).

        So if a particular group in our ten 5-shot groups is outside the 95% confidence interval calculated using Taylor and Grubs, then we will reject the group as being abnormal and recalculate the group size.

        – – – – – –
        Baseline

        (a) So we shoot ten 5-shot groups and get the average group size.

        (b) Use that to calculate a 95% CI.

        (c) If necessary, reject any wild shots, and reevaluate the average to get the benchmark.

        – – – – – –

        Now we shoot one 5 shot group by varying some factor and compare that to our 95% CI based on table 2 in paper by Taylor and Grubbs. What we don’t have is a good way to average 2, 3, or 4 of the 5-shots groups to get a better estimator. So what we need to make more progress is such tables for a small number of groups (less than 10) using a small number of shots per groups (3-10). I would guess that such tables exist; I just don’t know where such tables can be found. This will obviously limit how sensitive we can make the testing. So with just shooting one group my guess is that we’ll be limited to factors that either half or double the group size.


        • ~!@#$%^&

          Should have included assumptions:
          3A – Errors in horizontal and vertical deflection are equal and independent. Test for this by seeing if vertical spread is either 1/3 or 3 times the horizontal spread.

          Not real scientific, but a stake in the ground.


        • Herb,

          I think I need to brush up on my statistics CliffNotes and then re-read your post. I seriously fell off the wagon about half way through.

          Wouldn’t it be easier if we just shoot some groups, scan the results, and e-mail them to you? Then you can tell us what the heck to do next. You can be the Pyramyd Air Blog Accuracy Consultant.

          I’m only partially joking.

          – Orin


          • Orin,

            You should really design an experiment to answer a particular question. You shouldn’t just collect data and then try to figure out what it means. That is one of the points that I have been trying to share.

            The other major point is that a sound statistical analysis would generally require more data than most readers of this blog believe is necessary. Using a good statistical analysis isn’t about being whacko, it is about trying to avoid making unfounded statements.

            Not understanding statistics leaves you chasing your tail. Let’s say that, on average, I can shoot a 1 inch group at 10 yards with my RWS 34 and Hobby pellets. Ok, I shoot one 1/2 group this afternoon. That doesn’t mean that when everything is going right that I should be able to shoot 1/2 groups consistently. Conversely I shoot one 1.6 inch group. That doesn’t necessarily mean that I’m having a bad day. Due simply to statistical fluctuations, I can expect such variation. So I average all the groups from today and I get 0.87 inches. That is right about my 1 inch estimate so things are as expected.

            So the “best” group that I ever shoot with my RWS 34 and Hobby pellets is meaningless. If I want a smaller “best” group, then I just shoot my groups until I get one that I can boast about. Meantime my average group size stays at 1 inch! It is the average, or “expected group size,” that is a valid estimator, not the “best” group size.

            Hope this helps…
            Herb


            • Herb,

              It does, actually. I don’t think I every really thought about it like that. In the quest for accuracy, it is very easy to get wrapped up in what the “best” group looked like and keep chasing it. As you mentioned, without repeatability, what’s the point?

              Thanks for breaking it down in layman’s terms.

              – Orin



              • No doubt that there is some luck involved. But I could shoot the Olympic event every day all day for the rest of my and never come close to the score that an Olympic caliber shooter would have. I just don’t have the talent. Sort of like being 5’10”. I won’t ever make a center for the NBA.


        • Herb,

          On Friday I will show you why 5-shot groups simply won’t work. Ten five-shot groups contain the same number of rounds as five ten-shot groups, but they don’t show the same thing. A sample size of five is simply too small for this test. That is because of outlying problems that will/can occur in the shots after shot five. As I said, I will show you on Friday.

          Ten one-shot groups have no meaning, but one ten-shot group has a lot of meaning. Think of it that way.

          B.B.


          • BB,

            RE:5-shot versus 10-shot groups
            April 20, 2011 at 3:23 pm

            I totally agree that one 10 shot group is a better statistical estimator than one 5 shot group.

            But you’re:

            (1) Forgetting about including an analysis for flyers. More groups is definitely better for this.

            Do I shoot 1 flyer on average in every 12 shots , or one flyer every 200 shots?

            Using a 95% confidence interval, 1 group out of every 20 will be labeled ‘”abnormal” due to just chance alone (that is one “bad” shot in 100 for 5-shot groups, or 1 “bad” shot in every 200 for 10-shot groups.) But throwing out 5% of the data won’t skew the underlying distribution much. It will however greatly protect against one of my “senior” moment when shooting, or against a bad pellet since I don’t weigh and size sort them.

            So I arbitrarily choose 5-shot groups.

            (2) Also wrong about there being ONE “optimal” group size even ignoring flyers. There just isn’t ONE optimal group size.

            Think of it this way. With more groups the average over all the groups shot provides a better estimate of the “true” group size (known only to the oracle). But the more shots in a group, the more repeatable the group size measurement itself becomes. So it is balancing act.

            When some fixed number of shots we have to balance the two notions against one another. So we have to have some idea of how many shots that we are going to make in total, then split the shots between groups and shots within a group. For example:

            3 shots – all in one group (Agree that three 1-shot shot groups is useless!)

            5 shots – all in one group

            10 shots – two 5 shot groups. So to me averaging two 5-shot groups is a better estimator than one ten shot group. (But I EXPECT to shoot flyers. As John Wayne said “A man has got to know his limitations…” 😉 )

            900 shots – thirty 30 shot groups.

            I know the above are somewhat ridiculous, but I think that you should now understand the point I’m trying to make.

            – – – – – – –

            Having said all of that, I do know who is the tail and who is the dog!

            To keep setting the number of shots in a group to some random number prevents comparing easily results between blogs entries. If you want to set the bar at 10-shots groups, then that is your prerogative. It is your blog and you can set the “standard” whatever you want.



    • Herb,
      You appear to have some professional knowledge about the measurements you’d like to see us use during these exercises but in my lack of any knowledge in the field of statistics I have no idea what it is you want us to do. Could you tell us in layman’s terms what you expect?

      Could you explain to me what I need to do to establish a benchmark, and then how I determine what a 95% confidence level is?

      -Chuck


    • Herb,

      Everyone’s got their thing when it comes to shooting, but not everyone’s got the same thing.

      We try to do better than a monkey with a gun, but we know that perfection is unattainable 🙂

      Edith


      • RE: monkey with a gun

        I think BB’s blog is a lot better than a monkey with a gun of course. I really like to read this blog and I’ll be the first to say that I have learned a lot by being a participant. Being able to learning something new is why I continue reading. I truly apologize for not stating my appreciation more often.

        The other thing of course is that there is a lot of diversity here. Different people with different areas of expertise. For example Jane Hanson’s (think i got last name is right) contributions were fascinating. I miss her comments. How many blogs get a real live rocket scientist involved?


  2. B.B.

    Try a cheap and easy…
    Melt a pinhole in a piece of electrical tape and stick it on the lens of your glasses. It functions as a peep sight increasing the depth of field like increasing the f stop number an a camera does. It will take a little fooling around to get it in the right place.

    twotalon



    • g. austin,

      Again, you are missing the point. I already own a Merit adjustable iris. I’m not trying to shoot more accurately. I’m trying to see if wearing reading glasses has any positive effect on my shooting accurately, given the poor condition of my eyes.

      B.B.


    • g.austin,
      This looks like a nifty gadget but why would it cost so much ($67)? Are we that desperate? BTW, I had to block cookies 25 times to get to that link. I’m not singling them out, just making an observation of one of my pet peeves.
      -Chuck


    • I ordered one — but not from Brownell’s or the maker… We’ll see how long it takes to ship (with shipping it came to only $65).

      However… I believe it was stated that a peep sight had already been mounted on the rifle, so using an aperture on the glasses while looking through an aperture on the rifle sounds a bit, uhm, futile.

      What I’d consider more interesting, but not possible with that rifle, would if changing the /front/ sight from a post to a ring would have improved usage with a rear peep. Instead of balancing a bull on a post, centering it in a ring might be easier. A Daisy 853 with the selection of inserts would suffice, though 25 yards seems to be a tad long for the rifle’s power (pity I misplaced the inserts for my early 80s oddball — 953 barrel/receiver with 853 sights and stock — all I have IS the ring insert, not the post or disk; but then, I don’t have the range local either — 15 feet of living room is IT).


  3. BB, I appreciate your honest approach to things. In a world where anything can be faked, and I believe often is, it is refreshing to see someone who publishes the untouched results. If you read a lot of post and articles, you can get a feel for who you can trust and who might be stretching the truth a little. Thanks for the honest results.

    David Enoch


  4. B.B.

    I own pretty -8 diopters on my working right eye and compensate it with glasses -7,25. So, it seems I’m a “scope man”.
    I’ve got trouble shooting pistols and rifle with open sights as I cannot see target (distance) while clearly seeing post and dim notch. So I use my imagination – I “project” something bright and closer to me on a geometrical center of the target and aim to that spot laying closer to me. It helps quite well, I make some decent groups. Of course it works only with ringed contrast targets – but are there any others?
    I use a “shield” for hunting, just lite twotalon described, only made of blackened aluminum and mounted on my glasses, clicking it into and out of place. Its only drawback – it steals a bit of light.

    duskwight


  5. B.B.
    Are you sure your glasses are’nt to powerful? Iv’e been using a Williams peep sight on my IZH 60. my regular reading prescription is 3.00+ dioptor. But I use 1.25 for aperature sights for a good compromise between front sight and target. Without the glasses I see two front sights or a blob.
    loren


  6. Everyone,

    It seems my approach is confusing a lot of readers. Before a formal test is constructed, it is first subjected to peer review, which means one person describes the test and his peers try to poke holes in it, to improve the test design. That is what I was trying to get all of you to do. That was why I ran Part 1 of this discussion.

    I am soliciting your thoughts on how I conducted this test. I am not trying to shoot more accurately, except that shooting more accurately is the end goal of this entire series. But today I was simply describing how I went about testing the difference between wearing shooting glasses and not wearing them.

    As I indicated, the glasses don’t seem to have much impact on my shooting. Part two of this test will be run tomorrow, and it is a real eye-opener, to use a bad pun.

    What I would like you guys to do is look at what I did and describe things I overlooked, or things I didn’t do right to get the results I was after. And those who can do it would be more than welcome to try the test with me and report what they found.

    The goal here is to discover what works and what doesn’t. And when you see tomorrow’s results, I expect to see a nuclear meltdown.

    B.B.


    • BB

      OK, I think that I finally got it. If I am reading you right, I need to buy a new Bronco so that I can try out my results along similar lines with the rest of the test. This is what you meant right? (Say “yes.”)

      On a more serious note, I find that sometimes when I shoot I start out really hot, but then… it all kind of goes to heck. Other times I can’t do anything right at the start, but then I warm up or regain my focus or whatever, and then it starts to come together. That kind of thing could have an affect on the results of an accuracy test. You know this better than I of course, but I would like your take.

      I like this topic, by the way. Seems to drum up some interesting responses. All things considered, I hope that Brian from Idaho rejoins the discussion. He seems a good guy and added a good deal to the discussion, as well as having a good sense of humor. I just think he just got a wee bit unduly agitated.

      On a side note, Matt61 and Victor’s debates leave me in stitches. The discussion over the merits of women’s larger hips being a more stable platform for weapons such as Barretts, Howitzers etc. had me spraying beer from my nose.


      • Slinging Lead,

        “The discussion over the merits of women’s larger hips being a more stable platform for weapons such as Barretts, Howitzers etc…”

        Interesting. I don’t recall any discussion that I’ve had with anyone about these particular details. You must be thinking of someone else. Heck, I know nothing about Barretts or Howitzers. Maybe you just have a problem holding your beer? lol

        Victor


        • Sorry Victor, I WAS thinking of someone else. It was duskwight and Fred from PRoNJ. They were the ones with the offensive remarks. 😉 Sometimes even I get confused. I am mostly from Scottish descent however, so I don’t think the beer has anything to do with it.

          You were addressed in the very next paragraph. My bad.


          • Slinging Lead,

            No problem. I’ve just learned that I’m having to keep people honest here, since I’m now the target of liberal finger pointing. I haven’t done anything wrong, and yet my name now keeps popping up whenever someone decides that they want to point out undesirable behavior here. I will not be quieted, just because someone doesn’t know how to skip an individual post, or feel that they are the “chosen ones” to censure members of this blog. As far as I’m concerned, when B.B. or Edith tell me to stop posting, I will. That I was singled out and attacked was outright (putting it gently) silly. I’ve never attacked anyone, and won’t. Trust me, I can defend myself, but I won’t stoop so low as to try to reticule someone unless they’ve made repeated efforts against me to earn it.

            Victor




                • OK
                  I see that my off beat sense of humor was lost here.
                  I see your point about helping get more consistent and reliable results from the shooter himself. That’s not a problem with me.

                  twotalon


                  • Twotalon,
                    I actually saw the humor, but then wasn’t sure (I’m a little scatter-brained this morning). I communicate a lot with people all over the country via chat, and we miscommunicate from time to time because of something simple like punctuation errors. Some of them can be hilarious because a misplaced (or missing) comma can result in exact opposite meaning.
                    Victor


                    • Yeh, I can see that.
                      I let my high school grammar go to crap and am used to not getting too elaborate.
                      Must be my military training. Fast answers and fast results…YESTERDAY. Most of the time they don’t care how it gets done. Just so it gets done.

                      My sense of humor changes a lot so it can be hard to tell how to take me on a constant basis.

                      Now liberals…anything a liberal says is something I will find offensive no matter what it is.

                      twotalon


                • Victor,

                  I see a lot of comments that I assume are meant to be ribbing and humor. Sometimes, it’s not easy to discern humor from insults.

                  I scan all the comments to ensure things don’t get out of hand. If I’ve missed something, please bring it to my attention.

                  Thanks,
                  Edith


                  • Edith,
                    Thanks! I sure will. However, I believe that I can usually resolve things well enough. I am not one for personal attacks. I don’t shy away from conflict, but I don’t start trouble, even in my responses or reactions. In my work, I am usually under a microscope, so I have to respond to “concerns” all the time. Some concerns are valid, but not all. Some people just like playing “boss”. In any case, I don’t live in a vacuum, as I’m sure is the case for the rest of us here.
                    Victor


            • Cool, just so there is no bad blood.

              I am honest, I am not liberal, and I don’t finger point. I have not or would not accuse you of doing anything wrong. I have never associated your name with bad behavior. I skip all posts that bore me. Experience has taught me that I am not a “chosen one” in any aspect whatsoever. I never asked that you quit posting and never will. I did not single you out or attack you in any way. I thought I made my point that attacking you was silly, even if I got my references wrong. I do not have a beef with you.


              • Slinging Lead,
                My apologies. I know you made a simple mistake. My response to twotalon was not intended to indicate that you had done something wrong, only that this type of thing seems to keep happening, and if I don’t say something, others may get the impression that they have the “green light” to continue to single me out, or associate my name with bad behavior. REALLY, there is no problem between us, and I didn’t mean to imply that.
                Victor


              • OK, OK. Mea culpa. The stability factor is more in line with a 105mm Howitzer, not a 155mm. Victor, we all read so much and have so much going on in our lives, both on this blog and off, that it’s quite common to confuse one of us with someone else and misplace the owner of quote(s). Don’t take offense as it happens frequently. If anything, I should be offended as the credit for my “extremely clever quote” was attributed to another. You should be honored 🙂

                Fred PRoNJ


                • Fred PRoNJ,
                  LOL. As I mentioned above, I communicate a lot with people all over the country via chat, and we miscommunicate from time to time because of something simple like punctuation errors. Some of them can be hilarious because a misplaced (or missing) comma can result in exact opposite meaning.

                  I had a chat going with a project manager back east in which a missing comma did in fact imply the opposite of what I meant. This PM corrected me, and I then realized what the missing comma did. I then said, “That’s funny!”. The PM thought that I meant that her comment was funny (as in, I was making fun of her). I then had to clarify that I was talking about the effects of the missing comma.

                  Bottom line, the written word is great, but it sure does help sometimes to actually see someones face.
                  Victor


              • I need to make something clear: I am honest, and I am liberal. I had not previously noticed a political litmus test for being a good shooter or an honest person. I hope nobody is proposing one.

                –pete


                • Mellow out pete. You jump too fast.
                  I could have said the same thing about conservatives.
                  If you look at party “hard lines” you will find that you agree and disagree with both sides. Most people would find that they are really middle of the road on average with only a couple exterme views that they think puts them on one side or the other.

                  twotalon


                • Pete,
                  In my dealings with the City, I have purposely left politics out of all discussions because that only seems to bring out the worst in people. Sometimes it seems that there is no lower limit to the idiocy that political ideology can result in, because once people become mentally entrenched in it, real communications ceases. The original range masters left politics out of their business, and it seemed that everyone got along. Subsequent range masters made everything about politics, and alienated politicians who once looked at the program purely in terms of its value to the youth of the City.
                  Victor


          • Slinging Lead,
            I’m glad that you can appreciate what I write. As I’ve said before, since I started shooting springer’s, I feel like I’ve had to relearn how to shoot. The good news is that it all really comes back down to fundamentals. As a competitive marksman, we trained to master them, but at the same time, used equipment that somewhat masked out mistakes. With springer’s, it’s like being totally naked. Every flaw is exposed. Every single detail that I learned to shoot well is now magnified. I think that talking about those details are not only relevant, but also beneficial to newbies to our community here. Matt61 has further made me think about what I thought I knew. It’s possible that his questions to me, have helped me more than they’ve helped anyone else, but I hope that they might help others at least as much as they’ve helped me. Sometimes the value in what we say is not for us to judge.
            Victor


      • SL,

        I wrote to Brian via email, and he said he’s gone but may occasionally return to read. People come, people go. It happens.

        Regarding shooting when you’re hot and then turning cold…B.B. has off days, too, and realizes that it’s a bad day to do an accuracy test. That’s why we lay up a reserve of guns that he can test for other things…velocity, tuning, etc.

        Edith


  7. I have to admit – I was a bit suprised to see the subject of reading glasses come up in this test… as that is more of a shooter thing.

    That being said – I can only imagine that, if you feel more confident shooting with reading glasses – then go for it. If you feel confident, you’re going to be more relaxed…. you’re going to feel better about each shot… you wouldn’t be just ‘wondering’….

    The topic of pellet weights, and whether the pellets are ‘clean’ or not is an interesting subject. Personally, as a fairly new airgunner, I hadn’t put much real thought into that…. I just simply grab a pellet and go. Then again – I’m not a competitive shooter either… at least, not yet. (Been dabbling with the thought of Field Target)

    Personally I think – and this might also be considered a ‘shooter thing’… is ergonomics. When the rifle is held and aimed — how easy is it to keep the rifle steady and aimed without strain? I only have two air rifles – a Benjamin Trail NP XL 1100 in .22, and a Crosman Storm XT in .177. The Benjamin, is by far, the easier rifle to hold steady… My thought is that the Storm is either so light, or the foreend is so narrow – that every little minute bit of unsteadiness is amplified. What are other people’s thoughts on this? Do other people find a wider, heavier stock easier to hold steady?


    • Karsten

      Great point about ergonomics. I don’t think it is so much about the wideness, or weight, or thumbhole vs. pistolgrip. It is what seems to fit each unique person.

      I am fortunate enough to own an Air Arms TX200. The stock feels so good in my hands, it is like a comforting massage, followed by a peaceful nap. For my hands. It is on the heavy side, especially for offhand shooting -but the feel of the stock is always a joy to me. My second most accurate gun– the Marauder is like a cruel joke to my hands. It doesn’t feel good, and I have to reach too far to the trigger. Luckily she’s accurate so I haven’t ditched her yet.


      • Very interesting points, “Slinging Lead”,

        I just notice that – when I hold and aim the Storm XT, which (in my opinion) is a very light and slender rifle…. that, when looking through a scope, the aim point wanders quite wildly…. you have to really take your time to settle in, and by that time — you have to get your eyes off the scope to avoid “burn in”, and get your breathing back in order…

        It’s not impossible, but it takes a lot more concentration to land a good shot with the Storm XT, compared to a shot I would take on the Trail NP XL. There is still some wobble and wandering with the Trail — but, not nearly as wild… and not nearly as dramatic as the Storm XT.

        I feel comfortable, physically, with both rifles…. that’s why I tend to think it has something to do with the weight and width of the rifles….


        • I probably should mention that when I talk about this wandering and wobbling — I’m talking about when I take shots from an unsupported position; in particular from kneeling and standing unsupported positions… when I shoot, those two positions make up about 95% of my shots. When spring gets here (in Wisconsin) in earnest, then I will probably spend more time in unsupported prone positions….. I very rarely use a supported position — I do have a bi-pod on the Trail NP XL…. but, I’m going to have to invest in a better replacement. The current bi-pod I use, I think was made more for airsofters and such…. the force of the nitro piston is literally shaking the bi-pod apart. As such, I rarely use the bi-pod…


  8. BB, I can’t do the 25 yards but only 28′. Plus, I don’t wear reading glasses. Given my eyesight and prescription, I can use my regular glasses for reading by sliding them down my nose. The difference in focal length is enough for me to read just fine with. I’m afraid any participation on my part might skew what you’re looking for.

    On another topic, the Bronco, I introduced a buddy to air rifles last night and recommended the Bronco as his first rifle. He was very impressed with my HW 50S but cocking it was a bit of a struggle for him. We’ll see if we convert another one from rim and center fire to air rifles.

    Fred PRoNJ


  9. Under the catagory of “peer review” and how to “improve test design” I will offer my observations.

    I don’t think this needs to become a science fair experiment in order to ferret out some interesting results on what works and what is questionable for improving accuracy in shooting our airguns.

    Having said that, I think Herb has a point. There should be certain factors taken out of the equation before each experiment is conducted. Here’s my short list:

    1-check to make sure all the screws are tight (including mounts if using a scope)
    2-shoot 5 ??? warmup shots before proceeding with the test
    3-use same type of target for every experiment
    4-be extra concious of the same hold every time especially if your test bed is a springer (mine will be)

    I’m trying to keep this short and simple but wonder about noting temperature and wind on targets? Any other suggestions? Am I off base?

    kevin



    • Kevin,
      I have an oscillating floor fan in my indoor range that I could use for the windage experiment. That’s not why it’s there but it could be used for that purpose. I wish I wasn’t restricted to 10m but if I can find a bad enough pellet for my Bronco, so I can get some dramatic effects, maybe I can come up with some meaningful tests, too. The dang thing is just too accurate at 10m.
      -Chuck


    • Kevin,

      You have created the start of a good pre-test checklist. Every test has one.

      As for the targets all being uniform, there is merit in that, but if we mandate it, it will keep people from participating. So I’m for letting everyone use their own targets.

      As for “being extra-conscious of the hold technique” that is what separates what we are doing from a scientific experiment. Because we have no control group. We are using a one-over-the-world sample that excludes no one.

      Some think that it’s impossible to do, but I don’t believe it is. The artillery hold was the same thing. I can’t control how people really apply it, but it still seems to have almost universal success. And that is because it works.

      That is what we are searching for here–things that work. Things that, if applied the way we describe, will improve your accuracy.

      B.B.

      B.B.


  10. A question regarding your test with and with the reading glasses…

    I can understand the reasoning for using them – since it will you to see the scope reticule or iron sight with more clarity.

    However – just a random thought came to mind…. Isn’t the distance between your eye/glasses and the iron sight different than the distance you would normally have when using the reading glasses for reading a book? I don’t know the science behind it all — but, would that make some sort of difference – in terms of aiming and placing a shot?

    Would a different prescription, based on the distance between your eye and the iron sight, make any appreciable difference?



    • Karsten,
      Did you read this from yesterdays blog?

      http://www.bullseyepistol.com/wong1.htm

      It’s a shooter eye doctor’s report about what you’re asking. It’s lengthy but he does cover the effects of different prescriptions, and yes, it does make a difference based on slight diopter changes.

      At least scroll down to “3. REFRACTION” and read that.
      -Chuck



      • Dear “B.B.”,
        Would you seriously recommend that? I mean – I am near-sighted, and wear prescription lenses for that. I don’t know if reading glasses would be a good idea for me — as, if I took my glasses off… I can almost guarantee you that I wouldn’t see the target, much less the bulls-eye at 25 yards. 🙂

        I might see the target — but, it would just be a white, blurry mess.

        One thing I *have* noticed – if I took my glasses off, and look through a scope…. particularly at a target at very close range (5-10 meters)… the target is very crisp, but the reticule is so blurry that it’s totally unreliable… it blurs to the point of being a very faint, grey… rather than a crisp, black.

        Just an observation – that likely has no relevance to this test at all. 🙂


  11. I have 5 pr of 1.75 diopter reading glasses at last count.
    One sits perched atop my nose at this very moment 😉
    The others are in various gun cases and on my basement range bench.
    Past 4 or 5 feet I have near perfect vision. I am prone to a recurring eye ailment (eyeritis) that has, over time deteriorated my close up vision. My opthamologist says that if it wasn’t for this issue I’d have near prefect vision for someone 20 yrs my junior (I’m the perfect 57 years old).

    I first started wearing reading glasses about 10 years ago. I could read a book, if the print was large and crisp, but I was finding that too many books didn’t fall into that catergory…and even more of a push to the glasses was that with the switch to digital cameras in my photography there was just no way I could easily read the menu on the back of the cameras.
    And of course the use in target shooting was a given. Without reading glasses I’m looking at 3 fuzzy things (rear peep, front sight and target bull). With the glasses I have a perfectly sharp front sight, a somewhat fuzzy rear and bull. But I find that it is now so easy to center the fuzzy bull in the crystal clear front sight that shooting is a breeze.
    I have considered purchasing those expensive shooting glasses…but haven’t ante’d up yet. But one thing I did do that has helped was to cover the lens of my non dominant eye with black electrical tape (the lens on the glasses…not the lens on my eye 😉 ). By doing this I can keep both eyes open when shooting, which lessens eye strain due to squinting and makes a noticeable difference in sight clarity.


  12. B.B.,

    I’ve tried using reading glasses of various strengths, and they don’t work for me. I did, however, have a set of prescription glasses made to help me shoot pistol. They are progressives, and work really well for me. For rifle, I’m fine without glasses, as I can see beyond my extended arm just fine.

    There is something else that I feel is important to the discussion of vision and shooting, namely, conditioning (blood pressure and exercise). We can spend all the money in the world on the best equipment, or improve on our methods and techniques, but nothing will be as beneficial as exercise.

    I discovered that if I do some weight lifting just prior to reading, that my vision improves, and I can read without reading glasses. Sleep also helps. The overall benefits of exercise are enormous, and yet as we get older, we seem to do it less, when we need it the most. At a minimum, moderate exercises, like taking walks, will lower our pulse, which is a huge factor in our accuracy.

    Maybe this (taking walks, or riding a bike, etc.) is worth adding to your suite of tests? If after doing it for a week or two, does our accuracy improve?

    Victor


    • Victor

      This is an excellent test criteria. The more fit you are, the slower your heart rate is, because it is working more efficiently. Also vigorous exercise releases endorphins, which eventually leads to a very relaxed state. This would seem ideal for the focus needed for a person’s best target shooting.

      Another chapter for the book BB.


      • Slinging Lead,

        I would really like to see more of us taking better care of ourselves. Regular moderate exercise will do more for us than lots of prescription pills that we, or our doctors, think that we need. If shooting is a motivator, then fantastic. How we feel as we get older has more to do with activity level than age. The good news is that we don’t need to join a gym, or train like an athlete, to feel better. Taking a regular walk will do wonders. If weather doesn’t permit it year round, then consider a treadmill to be essential shooting equipment. 🙂

        Victor


        • How about getting a PCP and a hand pump, then shooting a lot? Or one of the hard cocking megamagnum springers? Either one is a lot of work.

          In the winter you just have to lift more beers when shooting time is limited.

          twotalon



            • The closest thing that I have done is setting pieces of gravel of various sizes on the top of my target stand then shooting them off. They have to be scrounged up out of the grass or simply replaced if lost or blown to bits.

              Did I ever say that I improvise? A bucket full of spent .22 brass would be good if I had it.

              twotalon


              • twotalon,

                We have crabapple trees all over our property. I used to cuss all the little apples that fell to the ground since they make such a mess. Now they have become cheap targets that explode. Even this time of year, after the squirrels have been scrounging for and feasting on them all winter, I can easily find several handfulls to set out on the targets. I like shriveled up grapes and cherry tomatoes too. Guess I’m sick. Everywhere I go I see things that would make great airgun targets.

                kevin


    • Victor,

      I have noticed that exercise improves eyesight, too. But it also increases heart rate, which isn’t so good.

      How do we balance between those two?

      B.B.


      • B.B.,
        I was just noting something that I recently observed (and was surprised by) regarding exercise just before reading, because it might tell us something about the overall effects of vision and physical condition. What I’m more interested in is exercise that provides more long term benefits, like walking, or even lifting light weights. These things will definitely help with our pulse, but over time might even help with our eyesight. Age should be expressed with more candles on our cake, and not necessarily so much how we feel. When we were young, we played more. When we stopped playing, we felt less young. Being able to shoot better is a great incentive, I think.
        Victor


  13. eric in ok says ive seen an ad in american rifleman for a vitamin thats suposed to improve your eye sight and therfore you accuracy,wondering if anyones tryed it. thanks eric


    • Eric,
      I haven’t seen that ad, but I did see an ad for a training program that claims to eliminate the need for reading glasses. I do know that some such programs really do work. My son was born with a severe vision disorder that not only caused him to see letters oriented wrong, but also caused severe headaches. Originally, the only recommendation that we were getting from doctors was surgery. We later found a doctor who was able to retrain his eyes. It worked. This was almost 20 years ago, and he still has to do the exercises on occasion. This is much better than what would have amounted to brain surgery.
      Victor


  14. RE: Test for reading glasses

    Ok there are a lot of variables here which are not nailed down which would be important if comparing multiple shooters, particularly if more than one type of rifle was to be used.

    (1) What is distance vision with reading glasses on?

    The assumption is that the reading glasses correct to 20/20 for near sight.

    (2) What is distance to rear sight and distance to front sight from check weld?

    To a practical extent, an infinite distance for your eye is about your arms length. So rear sight is probably not an infinite distance away, the front sight probably is, and at 25 yards the target certainly is.

    (3) What is the light intensity? Same at target as it is at the shooting position? (25 yards tends to tell me that this was done outdoors in sunlight.)

    Very bright light will contract pupils to minimum thus turning eye into more like a pin hole camera. Thus there is less need for glasses in very bright light. You can get too bright of course.

    Ideally we’d have eye sight tests at distance to rear sight, at distance to front sight, and at 25 yards to target.

    Hopefully this gives some more ideas on the notion.

    Herb


  15. victor,i have done eye exercises years ago ,I’m a cross shooter left eye right hand dominant had to train my right eye to act as dominate eye later could use ether at will,done great till i was put behind desk now i use my eyes close up too often and arms not long enough anymore.used to avoid caffeine before shoot doesn’t seem to mater anymore,might try vitamins to see if helps,bb didn’t say but the more things tryed the better the odds we can find what works.


  16. Afraid I can’t help with this test with my 20 foot range and offhand shooting and lack of reading glasses. Besides my IZH 61 is off to Mike Melick to fix the mainspring. But I’m glad to observe and learn and give my tribute….

    Why not a sliding scale of assessment adapted to the individual? People shoot with glasses and without and analyze the difference for themselves whether it is a quick glance at the targets, a comparison of group sizes or 95% confidence intervals. They are all tending in the same direction with just a different level of detail. As a groovy customer said to the Taco Bell employee who asked whether he wanted hot or mild sauce: “Whatever turns you on.”

    I actually have a question about quantitative statistics based on B.B.s results. How do you compare groups where the size is the same (based on measuring widest shots) but one has more clustered in the center? I guess you would say that one has a smaller standard deviation and common sense would tell you that it is a better group, but I’m not sure what else one would say about it.

    Victor, I sure appreciate all of your knowledge and generosity in sharing it and never have I sensed the slightest bit of ill-temper but very much the opposite.

    Slinging Lead, you crack me up and I’m sure that you must be hilarious in person. What was that comment about mugging the elderly…. Anyway, regarding the low center of gravity and body type generally, I’m moved to wonder about the difference in gun design now compared to before. One of the rationales for the M-16 design and the smaller caliber is that it is better-adapted for women (that argument also played a role in switching from .45 ACP to 9mm). However, we see in the Red Army snipers, women shooting Mosin Nagant rifles that were 9.5 pounds and 50+ inches overall and doing it well and looking mighty fetching in the process. So, the question is whether gun design is controlled by advances in ergonomics or whether we are getting wimpier. I’ve read literature to say that the army noticed a turning point in the 70s after which recruits got much flabbier and unconditioned.

    Duskwight, perhaps you know more about WWII sniping that can help me. As I watch Enemy at the Gates excerpts on YouTube and recall some other things, I get the impression that WWII sniping was more like what we would call law enforcement sniping today. While it took place with maximum bad intent and was not concerned about protecting hostages, it seemed to be more about stealth and concealment at short ranges. Even the celebrated Alvin York in WWI did his shooting at 50 yards or less I believe. There is one incident on a Pacific Island I recall where Marine snipers suppressed a machine gun position at 1200 yards, by firing into a bunker slit with a Springfield 1903A4, but that was an anomaly. It seems like the really long range shots didn’t appear until the era of Carlos Hathcock in Vietnam or today with the larger caliber sniper rifles. On the other hand, one hears about 800 yard+ shots in the Civil War so technology apparently was not the limiting factor and maybe the anecdotes of the World Wars were governed by circumstances.

    Matt61



    • RE: “How do you compare groups where the size is the same (based on measuring widest shots) but one has more clustered in the center?”

      Ok – I’ll take the bait. two things that you could do. Let’s assume that I’m shooting 5-shot groups.

      Given the 95% confidence interval (CI) that I post about earlier today about previously, the assumption is that the “bad” group is statistically abnormal. That is to say that it is outside the 95% CI.

      (1) Given that I have N 5-shot groups, I can just throw the “bad” result out. I end up with (N-1) experimental results.

      (2) I can measure the 4-shot group size and multiply by a fudge factor to increase the group size to what a 5-shot group size would be. Using this estimate as a “real” 5-shot group of course adds some extra error. But unless I have a lot of groups, this is probably better than just throwing away all 5-shots.

      This tweak is just a guess of course. This could be simulated on a computer. But this also gets twisted around what fraction of shots would be flyers and how much the distribution of a flyer differs from variations due to pure chance.


      • dah….

        I forgot the best option. You could possibly measure the each shot in the group individually. That would provide you with a better way of estimating the 5-shot group size.

        Note that I’m stuck on 5-shots assuming that was the benchmark. You are trying to compare against whatever benchmark that you established.


    • Matt,

      First I must note that “Enemy at the gates” is a tremendously horrible, untrue and stupid movie. The list of flaws, misconceptions and “oh-those-Russians” cliches and outright stupidity is ten miles long. When it appeared, it caused days of laughter. If you’re intrested, I can tranaslate you “top-100 bloopers” list, or “top-200 bloopers”for this movie. I believe it’s posible to make even 500-positions list for this Annaud’s “oeuvre”. The book by William Craig is better, at least less clicheed and a bit more true-to-life. I’ve heard stories about Stalingrad from my other Grandpa’s friend, who was 16 then and served as a liaison soldier (a courier) in 62nd Army and fought in its ranks, so I can tell Craig interprets the truth better.

      Ok, now let’s move to some facts.
      First of all – sniper shot looks bad for movies, they tend to film it as made from a closer distance (dramatic effect I suppose).

      Second – long or short shots depended on the theater. Landscape shapes war.

      Stalingrad was a perfect opportunity to use stealth and consealment tactics in ruins. And ruins also restricted shooting distance. Tell me that you won’t use that advantage – to get closer for an easier shot, especially when there’s a high probability to make it with little risk. 200-300 m or even closer was typical for Stalingrad

      On the other hand, when we speak about other parts of the front, like steppe, forest-steppe, field or tundra most common dictance was 300-400 meters – for both sides. Famous Soviet sniper Nomokonov had at least 1 kill at c.800 m distance, made across the water surface, many other Soviet snipers had at least one or two 900-1100 m kills. Typical “long” shots were 500-600 meters – those could be made by almost any sniper. 300 m in good weather was OK to kill a Nazi soldier through observation slit of a pillbox – there are enough records on that. And then again – if there’s no counter-sniper activity, everybody tried to cut the distance. Vasily Zaitsev preferred to start to work 800 m from German lines and worked with partners covering him and sectors, spotters, decoys and sack dummies. It was a real team work – against German team work. Then, if no resistance was discovered, he got closer and closer, sipping through the distance for a real work. And then – one shot and off, to sting elsewhere.

      Large caliber sniper rifles were used in WWII by Soviets as a “long hand” and counter-sniper. Those were PTRS and PTRD anti-tank rifles, sometimes fitted with typical PU sights or just improved iron sights. 14.5×114 – that says it all 🙂 They were used agains machine gun emplacements, sniper positions (brick walls were like paper to that bullet) gun crews etc. Grandpa was there when PTRD was used to kill a very annoiyng Finn through his armored shield disguised as a stump without entering his FOV and kill radius.

      I think that long range sniping began with sniper-purposed technology. Selected army rifles were (and are) good, but they are less “snipery” than a purpose-constructed and built rifle with match ammo. And more – reliable bright hi-mag scopes are late-60’s thing, and 3-4x scope for long-range precision shooting sounds like nonsence, as it doesn’t allow even reliable target acquisition at 1km+ distances.

      duskwight


  17. Robert from Arcade, sounds like you earned your money trapping. How would you compare the old Maglite flashlights to the tactical lithium powered flashlights of today? I’d say the long-handled Maglites would work for rapping an animal on the head of necessary. I have a memorable image of a bunch of guys at a bar (full of women dancing in spandex pants) with long-handled Maglite flashlights protruding from their cargo pockets, no doubt to see in the dark….

    On another note, I shudder to think of the damage by beaver teeth to a human body.

    Matt61


    • Matt: After the incident with the raccoon, I went with a small and cheap LED headlamp .Never liked those very expensive and heavy headlamps that are sold for hunting at night. I also carry a spare headlamp and a couple of small cheap LED flashlights. All run on AA or AAA batteries that are available nearly everywhere. The big mag lites are great as a sap,and I have a couple but they are way to heavy to use. I don’t have a real tactical lite,so I have no opinion on them, Robert.


      • Robert from Arcade,

        I too like the small, cheap headlamps that run on AA batteries. I fish at night for trophy brown trout. One hand on the rod the other for removing hooks (I’m a catch and release guy) doesn’t allow for holding a flashlight. I like the headlamps that have light intensity adjustments since for unhooking a fish you need only minimal light but for getting the row boat back to the correct spot on shore you need a higher setting to recognize in the dark where your launch and take out was/is.

        kevin


  18. I have a question….and I’m interested in the answer.It seems well suited for my fellow bloggers to answer.When a shooter uses a peep sight and post,and uses the six oclock hold…..can we expect
    more error on the vertical than horizontal? I ask because it seems to me that being horizontally off center would be very obvious in the sight picture compared to vertically.Vertically,it seems like it would be possible to accidentally overlap the bottom of the bull and the front post….especially
    if the bull is fuzzy due to focus on the front post.


    • Frank B,
      I think what you’re saying makes sense if we’re talking about a paper target with a fixed size bull. However, I wouldn’t expect the error to be much worse along the vertical, as opposed to the horizontal. The extent of the problem would probably be a function of lighting. I’ve tried such a setup and found it to be very sensitive to the position of the Sun.

      But this does bring up a question of what is the best way to use such a combination. Specifically, do you align the tip of the post with the center of the target and the rear peep, or at 6 o’clock, as you described? If you align the post at 6 o’clock, then you’re only sighting in for THAT particular size bull. If you align the tip of the post so that it’s centered with both the rear peep and the target, then the size of the target doesn’t matter. Also, I would think that the error would be equal for both windage and elevation.

      A problem that I have with my 397P is that the front post is kind of wide, so it limits my precision when centered with the peep and target, kind of like having reticles that are too thick. Good question.

      Victor


      • When using the post type front you need a point of reference, especially on live targets. With the HW aperture front if you color just the bead on the post and bead (pin head) insert orange ,you will have your reference. You can also color just the tip of any flat post . It is somewhat light sensitive in that, in very bright lite it will appear black. Also the size of the target must be taken into consideration.A large thick post and or bead will obscure the target. An aperture front is better for bulls eye shooting because you can encircle the bull. It will also work when shooting rodents and small birds through the head.


      • I allowed my 392 to go home with someone else….but when I still owned it I remember the post width
        being an issue for me.My solution was to shape it with a mill bastard file.I scribed lines on each side to mark the bottom of the taper.From the top I scribed a center line.The finished post did alot to increase my confidence in the point of aim.It also gave me reference points for kentucky windage
        (really for shooting different distances,not different wind values).Definitely not for everyone,but it did work as intended! I did the same with a 1377 and it worked great with the supplied rear peep
        that was accessed by flipping the rear notch upside down.


    • Frank B.,

      VERY interesting and pertinent question.

      I’ve shot more guns with varying types of open sights and peep sights in the last few weeks than I ever have in my entire life. That doesn’t make me qualified to answer your question but I’ll offer my observations.

      The tendancy to vertical string can be more than horizontal depending on your target and your post. If your post is installed on a ramp it’s tougher for me to encircle the post exactly each time. If your post is a squared off blade (not a corn or roof type) no vertical stringing occurs IF you have a correct sight picture. For me, two things have to exist for a square blade post to be accurate using a six o’clock hold. First, the blade must equal the width of the bullseye. Second, I must adjust the sights so that a sliver of light exists between the blade and the bull but both are completely, equally encircled by the rear peep.

      For me, a metal ring element or plastic ring element as front sight inserts are easier for accuracy. A ring within a ring. If I’m shooting at something other than a black ten meter bull (like an orange dot on a shoot-n-c, or red mark made by a red felt tip pen on white paper) then I really like a bead sight as an insert.

      Different sight inserts that dictate differing holds on a bull could be a whole blog topic. I’m probably doing it wrong.

      Summary….yes, vertical stringing in my experience is more pronounced depending on your type of post/front sight and depending on your target.

      kevin


      • Thanks Kevin! That is something I hadn’t yet experienced,with my propensity to plink…..I have limited my exposure to peep sights.What you said about post width,and filling the sight picture with the bull and post….. makes obvious sense.I do wish to become proficient with match sights.More practice is clearly warranted (when isn’t it?) and as my comfort level increases,so will my enjoyment!


        • Frank B.,

          Confession.

          I like shooting any gun at any distance. Ultimately, I HAVE to know what accuracy/precision the gun is capable of. My downfall. I enjoy plinking but at some point I need to know what the gun can do.

          I have limited exposure to rear, match, aperture sights. I’m at the bottom of what I anticipate will be a very steep learning curve. I’m fortunate in that I shoot regularly with a few guys that are 10 meter gun nuts. Marshall is a better shot than I am with almost any gun but his preferred medium is 10 meter guns with match sights and he’s a challenge to beat. He’s enough of a gentleman to give me tips though.

          I need more practice too.

          kevin


          • I should clarify,just because “plink” has many potential definitions…I like to shoot blank cardboard.
            Think of it like doodling! I like to use pellet holes as targets,or sometimes the tacks I use to hold the targets.With so many airguns,it’s quite a challenge to jump around from one to another,and still shoot proficiently.I also have an iron plate for stopping bigbore shots,and a .22 grade spinner set.I stopped using drywall screw heads as targets,because the lead really fills in the head and can be nearly impossible to get a bit in to remove.


  19. BB is over fifty; of course he needs reading glasses. It is extremely common for eyesight, once you’re in the reading-glasses-class, to change fairly suddenly — the readers you used yesterday with pleasure won’t work today because the shape of the eyeball changed or the shape of the lens did the same. Before getting a new prescription wait a month or two for things to stabilize.

    After I get the cataract in my shooting eye removed and a plastic insert mounted, my eye doctor says he will be happy to fit me with shooting lenses if I want to bring a rifle and pistol to his office. Sounds like a plan.

    In the mean time he offers this advice: If you have a set of driving glasses, you can approximate a shooting prescription by wearing the driving glasses, and then stacking a pair of cheap readers in front of them, approximately +1.0 diopter for pistol and +1.5 diopter for rifle. Yes, you’ll look and feel funny wearing two glasses at the same time, but it works passably well. If you like you can tape or glue one lens out of the drugstore readers onto the lens of the driving glasses. This is crude enough of a solution to where you can get away with your old driving prescription so you don’t ruin a useful pair of glasses.

    If you cannot see the front sight and look through the rear sight, you can’t shoot accurately; I don’t think you need an experiment to tell you that. The usual recommendation is not to let your eyes focus back and forth between front sight and target, but to concentrate on the front sight and allow the target to blur as it will. Your instincts will take over and tell you when to break the shot. This isn’t my idea; you’ll find it in every book on target shooting.

    As to group size measurements: 5 shots is too few to show up problems with grouping reliably; if I understand the Grubbs papers, 7 is probably optimum if you’re using maximum spread. I would be much more impressed by 10 shot groups and the size of a hole that covered one half of the impacts (this is what is used in measuring accuracy of guided missiles: the circular error probable [CEP]). You have to have a system for excluding “oh, Hell!” shots where you know you should have aborted the shot, but fired anyway and knew that the shot would be wild if you want to use the maximum value of c-t-c measurements.

    Matt61 asks how you compare groups where the widest spacing is the same, but the shots in one group are more tightly concentrated in the center. You need to be able to exclude known fliers. Or be able to reduce the weight they are given. That’s why the standard deviation, or its simple surrogate, the CEP, is a much better measure.

    Plinking is fun, and it can help relieve stress, but if you really want to learn which variables matter, you have to do a controlled experiment!

    –pete




  20. Regarding shooting with reading glasses: Has anyone else seen those thin plastic “bi-focal” lenses that you can stick on your glasses. Some people stick them on their sunglasses to be able to read. One of the guys that I go diving with sticks them inside his dive mask so he can read his guages. These can be bought at walgreens in varius strengths. Maybe they could be used for some of the purposes mentioned on this blog. They could certainly be stuck anywhere on a pair of glasses and even just on one lens. One could also experinemt with various strengths to get the right focal length.
    -Chuck


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