Pellet velocity versus accuracy test: Part 10

by B.B. Pelletier

Announcement: Kevin Currie is this week’s winner of Pyramyd Air’s Big Shot of the Week on their facebook page. He’ll receive a $50 Pyramyd Air gift card.

Kevin Currie is shown shooting a tuned .177 Gamo CFX with his son and dog. He says his CFX is scary accurate!

Part 1
Part 2
Part 3
Part 4
Part 5
Part 6
Part 7
Part 8
Part 9

Merry Christmas!
For those who celebrate Christmas, Merry Christmas from Edith and me! This is our last opportunity to wish you a Merry Christmas before Sunday, but I would like to hear on Monday from anyone who received an airgun, airgun-related gift or a firearm for Christmas. I’ll tell you what I got, too.

Today, we’ll look at the results of this test to see if there’s a direct inverse relationship between pellet velocity and accuracy. I’ll start with the results by pellet and see where that goes.

A word about the shooting technique
The first accuracy test I did was in Part 2 of this report. I found fault with that test, though, because of how I was shooting. I wasn’t using the scope level on the gun all the time, and I also wasn’t “seasoning” the bore by shooting several shots before starting a group. Some pellets seemed to need the seasoning, while with others it didn’t seem to matter as much. I reshot the entire first accuracy test and seasoned the bore for every pellet, plus I paid attention to the scope level.

The need for seasoning seemed to go away as testing progressed, but the scope level was always consulted for every shot. I know that the level improved the performance of every pellet that was shot. The jury is still out on the seasoning issue.

All the accuracy results seen here are not from the first time I shot the rifle, but the second. All were shot at the velocities indicated. Just the shooting techniques were adjusted as indicated.

Beeman Devastators
In this test, the 7.1-grain Beeman Devastator was the “little pellet that could.” From the start, when it was averaging 1,216 f.p.s., this lightweight hunting pellet produced 10-shot groups under three-quarters of an inch at 25 yards. That went against the popular belief that supersonic velocities are harmful to accuracy.

The Devastator turned in the following performance at 25 yards.

Velocity (f.p.s.)….Group size
1,216………………….0.743″
1,123………………….0.616″
973……………………0.724″
772……………………1.073″

Okay, you don’t need a graph to see a problem here! This pellet is obviously way more accurate at 1,123 f.p.s. than it is at 772 f.p.s. Theory says that shouldn’t be because the first velocity is breaking the sound barrier, which is where all the accuracy gremlins are supposed to live.

Looking at the group size in relation to the velocity, it appears that 1,123 f.p.s. is the most accurate velocity for this pellet in this gun. That would entirely negate the theory that velocity destroys accuracy. So, if there is such a relationship, it must be subordinate to and less influential than some other influence. I think that other influence might be vibration, but that’s just a guess.

Crosman Premier lites
The 7.9-grain Crosman Premier lite was the next pellet I tested. Here are the results of all four tests at 25 yards.

Velocity (f.p.s.)…Group size
1,134………………….0.778″
1,057………………….0.754″
915…………………….0.747″
732…………………….0.593″

The Premiers did give a linear relationship between velocity and group size, though the two groups from the middle two velocities are so close in size that they could be the same. Measuring error is greater than the difference between these two groups.

The group at the lowest velocity is obviously the best of the four and by a wide margin. The data from this pellet isn’t clear as to what is causing the accuracy improvement. It could be either velocity or vibration. However, at 915 f.p.s., the pellet is going slow enough to be out of the transonic region, while at 1,057 f.p.s. it isn’t. I would have expected to see an accuracy gain at that lower velocity that’s greater than what we see here if the real problem is just velocity.

Beeman Kodiaks
Next, I shot the heavyweight Beeman Kodiak pellet. It proved to be the most accurate pellet of this test and the only one that turned in a group smaller than a half inch. Please bear in mind that these are all 10-shot groups and are about 60 percent larger than they would be if they were only five shots. I didn’t shoot 10 shots for that reason — but because, in doing so, I reduced the probability error significantly. In short, I can trust that the group sizes shown are closer to reality that if I had shot two 5-shot groups and averaged them.

Kodiaks shot tight right from the start, even though the first group of pellets was actually close to or just within the transonic range. Since I didn’t keep atmospheric data for each day I shot, I can’t say where the sound barrier was exactly; and the transonic region, which is 0.8 mach to 1.5 mach, is calculated based on that. In practical terms, I know that 992 f.p.s. is pretty darn close to transonic, because the sound barrier can be anywhere from 1,050 f.p.s. to 1,125 f.p.s. depending on the temperature and humidity where I shoot.

Velocity (f.p.s.)…Group size
992…………………….0.633″
937…………………….0.628″
819…………………….0.472″
658…………………….0.864″

However, the groups don’t seem to support the velocity/accuracy relationship very well. It’s true that the first and second groups are too close to really say which is larger than the other, but the velocities at which they were shot are very important. One borders on the transonic, while the other is probably slower than transonic.

But look at that third group! When the velocity averages 819 f.p.s., the Kodiak loves this rifle! Is that a velocity thing or is that influenced by the harmonics of the rifle at that power level? I’m inclined to think that it’s the latter, though we do not have enough data to prove it.

The last group is the worst, though the velocity is getting pretty low for a pellet this long and heavy. We don’t know much from these results, either. But if it does turn out to be harmonics over velocity, then this pellet is probably the best one for the rifle, and the Harmonic Optimized Tuning System (HOTS) needs to be adjusted for it at around 900 f.p.s.

Eun Jin
The 16.1-grain Eun Jin pellet is too heavy for the power potential of this air rifle. Although the Whiscombe JW 75 is a 30 foot-pound air rifle — that’s only in .25 caliber — when the heaviest pellets are used. In .177, it’s much closer to 20 foot-pounds and is, therefore, too weak to drive the 16.1-grain .177 Eun Jin fast enough for accuracy.

Velocity (f.p.s.)…Group size
726…………………….0.798″
687…………………….1.118″
618…………………….1.270″
501…………………….1.724″

Starting with the second group, I could tell that the Eun Jins weren’t going to do well. Like the Kodiaks, they’re also too long and heavy to make any conclusions regarding velocity versus harmonics. They just don’t give enough speed in this rifle to properly examine the velocity question.

A different look at the data
The “sweet spot” was different for every pellet. Each pellet had one velocity at which it grouped the best; disregarding the actual velocity, it went like this:

Fastest was best—>Eun Jin
Second fastest was best—>Devastator
Third fastest was best—>Kodiak
Slowest was best—>Premier lite

That, by itself, is a pretty good indicator that supersonic speed isn’t a problem, since the Devastator was supersonic when it produced its best group. One thing you cannot do is compare the group sizes…one to another…between the pellets. Let each pellet stand alone because there are far too many variables to make a cross comparison like that.

Was the Whiscombe a valid testbed?
Some thought the Whiscombe was the wrong gun to use because it’s so inherently accurate. I disagree. I think its accuracy makes the results all the more valid. Besides, controlling many of the magnum breakbarrel springers is too difficult and gets in the way of testing. They require perfect hold technique for every shot. The Whiscombe is much easier to control, which takes that variable out of the equation.

Some felt that only a pneumatic should be used since harmonics seemed to be causing accuracy errors. Well…that was the point of testing! Now we know a little more about how the pellets respond to supersonic speed, and it seems to me that it doesn’t matter as much as many, including me, have believed. People don’t just shoot PCPs. I do plan on testing this same sort of thing with a PCP whose velocity I can control over a wide range, and those results will also be interesting — but they don’t negate the value of testing a springer.

I used the Whiscombe for this test because, even when I altered the velocity, the harmonics of the gun remained the same. The powerplant always ran at full power, regardless of how fast it shot. And the barrel was always the same, too. The only thing that changed was the velocity.

What comes next?
I’m sure some of you will have additional interpretations to make about this test, and now is the time to make them known. My next step is to use the rifle as it is currently set up and adjust the HOTS to see what I can do to the size of the Beeman Devastator group. I’m thinking the HOTS can be adjusted to shrink it significantly. I have a procedure in mind to cut the time it takes to adjust the rifle because this can take hours if you aren’t careful! I’ll share that procedure with you in that report.

If I’m right about being able to tune the HOTS to get a small group at the average of 772 f.p.s., then the next thing I’ll do is shoot another group with the bubble level taped to hide the bubble. I won’t intentionally try to enlarge the group, but I just won’t be able to consult the bubble for every shot. That will result in another group that can be compared with the best group I’m able to shoot when the HOTS is tuned, because it will still be tuned for that group.

Finally, perhaps one additional test is needed. I’ll set the rifle to shoot Kodiaks in the high 800 f.p.s. range and adjust the HOTS for the best accuracy. When I get the best group, I’ll shoot one group of weight-sorted pellets against another group of pellets selected straight from the tin.

When all of this is completed, I should be able to state what I think are the most important components of accuracy. You’ll be able to see how much difference these things really have on group size. Most of you can’t adjust the harmonics of your spring guns, so you need to find the one pellet that shoots the best. Perhaps it’s time someone made a generic harmonic tuner for springers, again.

98 thoughts on “Pellet velocity versus accuracy test: Part 10

  1. These results are so counter intuitive… The fact that the single best overall group was achieved at 819fps had my jaw dropped. It brings so many more questions. I really can’t wait to see the results with a PCP to see if the pellet is having problems with super fast travel in air or if the innacuracy (that we tought was there at very velocity) is due to the power plant used to proppel the pellet.
    I’m guessing the answer will be “it depends”.

    Have a happy holidays to everyone and be safe.

    B.B. I don’t know what I’ll be getting for Christmas but even if it’s socks there always my birthday coming a few days later so all hope won’t be lost. Still I’m guessing some CD’s/DVD’s and a MTM Predator will be under the tree for me.
    With a Dan Wesson and the small Kimar 760 air rifle coming for my birthday.

    Last day of work tommorow then it’s 2 weeks off with the kids and it’s the best gift I could ever get.

    J-F


  2. BB,

    Merry Christmas to you and Edith. This test is just what the pellet-using world needs, some experimental data. I do have a couple of issues, though.

    Regarding the CPL’s, you say:
    “The group at the lowest velocity is obviously the best of the four and by a wide margin. The data from this pellet isn’t clear as to what is causing the accuracy improvement. It could be either velocity or vibration. However, at 915 f.p.s., the pellet is going slow enough to be out of the transonic region, while at 1,057 f.p.s. it isn’t. ”
    Yet, regarding the Kodiaks, you say this:
    “Since I didn’t keep atmospheric data for each day I shot, I can’t say where the sound barrier was exactly; and the transonic region, which is 0.8 mach to 1.5 [sic] mach, is calculated based on that. In practical terms, I know that 992 f.p.s. is pretty darn close to transonic, because the sound barrier can be anywhere from 1,050 f.p.s. to 1,125 f.p.s. depending on the temperature and humidity where I shoot.”

    Doing some math:
    0.8*1050 = 840
    0.8*1125=900

    The lower boundary of the transonic region is 900 fps at most, possibly as low as 840fps. So, at 915fps, the CPL’s are still within the transonic region.

    Regarding the Devestators, you say:
    “Looking at the group size in relation to the velocity, it appears that 1,123 f.p.s. is the most accurate velocity for this pellet in this gun. That would entirely negate the theory that velocity destroys accuracy. So, if there is such a relationship, it must be subordinate to and less influential than some other influence. I think that other influence might be vibration, but that’s just a guess.”

    The thesis that “velocity destroys accuracy” is patently ludicrous, anyway, if we consider different shapes. Boat-tail, spitzer pointed bullets do quite well at insanely high velocities. I didn’t realize you were out to prove or disprove anything — the title of the test is simply “Pellet Velocity versus Accuracy Test”. Given the Devestator data, we should consider that something about their shape is compatible with transonic velocities and incompatible with subsonic ones. My hypothesis is that vibration occurs as a possible factor because of the presence of the HOTS system, but that is, likewise, just a guess :).

    I think the use of the HOTS to try to eliminate or minimize error is a good idea, but as the data stand now, it seems that the Devestators are well-stabilized and thus accurate in the transonic region, that the CPL’s are only adequately stabilized in [a large, tested part of] the subsonic region, that the Kodiaks are stable for a large percentage of the subsonic region but not all , and that the Eu Jins are only stable for an unknown but likely small extent of the subsonic region. My guess is that the Kodiaks and Eu Jins are not entirely stabilized by drag and that twist rate is also a factor, but I look forward to seeing the HOTS testing and hearing alternative theories. Good work.


    • BG_Farmer,

      You did what I asked and really gave some thought to this report! Good for you!

      On the transonic region, I confess I didn’t do the math. It was a SWAG.

      On the issue of shapes and their performance in velocity the only thing we are considering in this report is the diabolo pellet. Yes there are shapes that travel best supersonic, but none of them are diabolo pellet shapes. So we have to stick with what we have. I’m not extending this test to firearm bullets.

      As far as the Devastators go, I guess the next experiment will show if they are affected by harmonics.

      As for the rest of what you say, I don’t want to draw any conclusions from this early data. We still have so much more to test.

      But when it is all over I would like to know what velocity does to the diabolo shape and how harmonics play into the equation. I have an opinion right now, but it’s too early to say anything with so much more testing required.

      B.B.


      • BB,
        I didn’t mean to jump to conclusions at the end, I was just trying to characterize the data as it seems to me, but objectivity is hard to attain, much less maintain and I’m not sure even my modest goal there was achieved :)! I’m interested to see what happens with the HOTS, as it should improve some of the groups quite a bit, but I’m glad you didn’t mess with it initially, because it might have obscured relevant data also, as the differences are small in some cases (and in a few probably not significant). One thing at a time. Regarding the HOTS, I assume you have to tune it for each pellet and each velocity (or perform some kind of test that proves that extra step unnecessary) — you’ve got a lot of work to do, young man :)!

        You’ve already done quite a bit — the testing would have been worthwhile just to see the Devastator results. Whatever is going on there, they are challenging “conventional wisdom”.


        • BG_Farmer,

          I don’t intend tuning the HOTS for every pellet at every velocity. That would take too long, since it can take a couple hours just to tune one pellet and velocity. I think the Devastator will show us whether it’s velocity or harmonics, but if it doesn’t I guess I’ll have to try something else.

          B.B.


  3. B.B.,

    I’m thrilled by this report. It has finally made something very clear to me that has concerned me greatly….

    You’re back.

    With all due respect you couldn’t have compiled the information necessary nor have written such a lucid, detailed report on such a complicated subject 18 months ago.

    Todays article is among the best you’ve ever written since it accurately summarizes months of testing as well as objectively and dispassionately suggesting options for future tests. A very complicated and advanced airgunning subject. This is a much easier read than trigger to target but just as relevant.

    Welcome back. Best Christmas present you could give me.

    ps-what is the rationale behind re-introducing an unnecessary variable into this complicated equation like cant by “shooting another group with the bubble level taped to hide the bubble”??

    kevin


    • Kevin,

      As Edith was sitting on the couch last night and editing this report she made me stop her favorite movie, “Thor”, and discuss the various aspects of harmonics, twist rates, and even the alloy of steel used in airgun barrels. This came from Edith, who usually is happy when I write a few “Tom-isms”. So I knew I was onto something. I knew today’s report was going to generate a LOT of discussion.

      Yes, I agree with you. I am back. Three days ago I was finally able to complete an easy Sudoku puzzle that has had me stumped since I got sick. The next day I did a second puzzle in about an hour. So something that took 18 months has now shrunk to one hour. I knew then that my cognitive faculties had started to return. It’s nice to be able to think again.

      The bubble level is part of yet a further look into what affects accuracy. You may remember a couple years ago that I wanted to conduct the ultimate accuracy test, but nobody wanted me to? Well, I have done it without giving it a name. And readers are having the fun I thought they would. They just didn’t want to be told up front that they were embarking on a long and arduous journey. Kind of like Shrek talking Donkey across the flimsy bridge over the lava mote.

      B.B.



    • I’m surprised no one’s offering a service, to take a Red Ryder and install a compass and the “thing which tells time” into the stock for a modest fee.


      • flobert

        That is an excellent idea. I am going to be on the lookout for a small, thin compass I can install on my Red Ryder. That way, I won’t get lost on my way back from the cattle drive. If I find one, I’ll let you know how it works.


        • SL,

          This was actually done by BB gunners in the 1990s. And even Daisy did it, since Red Ryders never had compasses, originally. Daisy bought the compasses for the Christmas Story Red Ryders in small lots, so there are many different kinds of compasses in those stocks.

          But back to the hobbyists, they did as you suggested and put compasses into Red Ryder Stocks.

          And even the trombone-action Buck Jones model that did have the compass experienced a surge in popularity after A Christmas Story hit the silver screen.

          B.B.


          • Brr! 33 degrees inside my place right now and for some reason the Internet is down, so I’m sitting in one of the (many) junk cars around here using some wifi signal I found. At least the whole internet’s not down (yet).

            But you also have to have the “thing which tells time” (sundial!)

            Now there’s a crow sitting on top of the truck right over my head!



              • And compromise that junk truck’s future potential as a place to store chicken feed, or oil etc for the tractor?

                I’m keeping my chicken feed right now in a Baja bug that will never bug again, but it’s a good sheep-proof storage areas for those luscious buckets of pellets and corn.

                The Apocalypse is here, it’s just not widely distributed yet.


        • Slinging Lead,

          I actually did install a small compass into the stock of my Ruger AirHawk after losing one too many other compasses during a squirrel hunts through some particularly thick briars. It’s just a cheap, chinese one made from plastic, but it works for the most part. It’s been handy.


          • Bobby

            I should have known somebody around here had already done it. And I’m not surprised it was you.

            I don’t suppose the metal in the gun throws off the compass readings?


            • I think that it does throw it off, but not by much — maybe 15 deg or so. Heck, the thing is not exactly a precision instrument, so it’s possible that it is off by that much naturally. Still, that’s close enough to get me out of the woods if necessary :-)


  4. Does this prove merely that there are “sweet spots” in velocity for each pellet? Remember all the complex vibrations and things happening in the average airgun before and as the pellet travels the barrel and then the vibrations of the barrel itself, which may be a bigger factor for a 6-7 grain pellet than for a 40-grain .22 lr bullet.



      • Indeed!

        I’m thinking of those experiments that guy was going, early 90′s, he was in the Los Angeles area, he was making barrels that had the true barrel in the middle and then concentric layers of other alloys/metals, they had no “ring” to them. Just went clunk. He was pretty old and I think died a short while after I met him, I wonder if this line of research died with him?




    • Steve,

      That’s what we think. The extreme wind buffeting of the transonic region is what we think moves each pellet enough to cause a loss of accuracy. But how big a loss is what we don’t know.

      The way this test is turning out so far, the harmonics of the gun seem to disturb accuracy more than the speed. But we have a lot more to discover.

      B.B.


  5. Ever since you tested the MP513 about 5 years ago I’ve been a bit skeptical of how badly high velocity impacts accuracy.

    http://www.pyramydair.com/blog/2006/12/izh-mp-513m-air-rifle-part-2.html

    The MP513 is a lightweight gun that is very powerful for a springer. It shoots harshly but is capable of very good accuracy. It was spitting out Crosman Premiers at over 930fps, yet look at the groups. The one target you show has 4 CP’s going into a group not much more than 1/8″ at 30 yards… with a single shot spoiling it. You noted that this happened a number of times.

    Not sure why you always had that odd flyer. But it seemed to me that if transonic velocities were really impacting accuracy, the effect would have been a lot more random and you wouldn’t have had such tremendous consistency with most of those shots.


    • Vince,

      Yeah, well when I said I didn’t know everything (or even MUCH) about airguns a couple days ago,l people started chiding me for being modest. Here is another example of my modesty.

      I’m learning this stuff as I go — the same as everyone else. I did this report specifically to examine an old saw that has been said so many times that we all believed it.

      I still DO believe that velocity affects accuracy — just not to the extent we may have believed. And harmonics plays an even bigger role than has been suspected.

      B.B.


      • That’s why you’ll never make a good politician… when it looks like facts might disagree with your opinions, you’re willing to rethink the opinions rather than reject the facts. Many “gurus” quite prefer to stick to their opinions no matter what.

        Thanks for the excellent study. I don’t think we’d find this sort of testing and analysis anywhere else.


  6. 1) Merry Christmas and Happy New Year to you, Edith, and all others who celebrate such things.
    2) Would be interested to hear how the PVC trap is doing, given the amount of shooting you do.
    3) As to the article. A long time ago, in a galaxy far, far, away, a test was conducted using 2 chronographs. One was positioned near the muzzle, one at the target. (30 yards away) At the time, the idea was to see what the effective delivered energy was versus the muzzle energy for a given pellet. So, if you are up to more testing this might be a next step.

    Please forgive me if the following detail was missed in your report…

    If the lightweight pellets that were tested stayed supersonic over the entire distance you were shooting at, they never transitioned and therefore didn’t have their flight disturbed.


    • JGC,

      The PVC trap has passed the thousand-shot mark and is probably over two-thousand shots now. It has taken up to 50 foot-pounds thus far and is holding up well.

      Light pellets decelerate much sooner than you think. I doubt is any of them made it to 25 yards supersonic, but that might be something to test.

      B.B.


    • I.A.W. Chairgun…
      Let’s say the Devastators had the B.C. of the CPL. Which they WON’T have due to weight and shape…
      It would take them a whopping 13 yds to slow down to the same speed as the CPL leave the muzzle….which is right at the speed of sound.

      So, no way it is going to happen. Not clear to 25 yds.

      twotalon


    • And having another look…
      Estimation of B.C. of the Devastators to be about .01. To drop to the velocity of the CPL at the muzzle (which is about the speed of sound) will be……
      5.5 yds.
      twotalon


  7. You know, after watching the youtube videos the other week in super slow motion of a breakbarrel rifle barrel going through a sine wave vibration upon firing, I wonder what the Whiscombe barrel is doing? I would surmise the sine wave vibration is more violent for high powered springers than for low powered. Now I’m wondering if accuracy is a function of this vibration which is more violent at high power than at low power (consider 10M rifles – the spring piston ones – which shoot at fairly low velocities and are fairly heavy and perhaps don’t suffer this severe a vibration) and the sound barrier is playing more of a minor role?

    Good stuff to ponder!! One question, BB. What if I bought myself some airgun related presents for the holidays? You still want to hear about those on Monday?

    Happy Holidays to all and a Healthy New Year!!!! As my friend Harry used to say, “if you’re healthy, you’re wealthy!”

    Fred PRoNJ


    • fred,

      Edith bought me a nice firearm-related gift, but also one that is so specific that I had to make the order. Of course stuff like that still counts.

      If you are in doubt, think of little Ralphie. Let him be your guide.

      B,B.



    • Why are you still in the Peoples Republic? GET OUT BEFORE IT’S TOO LATE AND THEY COME TO YOUR DOOR AND TAKE YOUR BB GUN AND EVERY THING ELSE.I did and it’s great to be free.


      • He might have a better job, life, and opportunities to shoot than otherwise.

        I left CA for AZ a few years ago. I was out there a year, it was all I could stand.

        Everyone was on Food Stamps and Welfare. 96% Caucasian and Republican, and all locked on to the gov’t teet.

        Crime was high.

        Taxes were HIGH. 10%-12% and everything is taxed even food.

        No opportunities to shoot. Where I am now, back in California, I can do tons of shooting. Airguns and some lower-powered .22′s here, a range up the road for smallbore, pistol, high-power rifle, you name it.

        Great hunting and fishing all over. Tons of game, birds, fish.

        A lot more people around me who are proud to work for a living.



  8. This discussion also has information in it that can be useful for firearms shooters. Maybe more than they realize. The discussion on .22 cal centerfire varmit rifles regarding twist and bullet wts. that we were kicking around a couple weeks ago has common roots. Anyway, BB you and Edith have a Merry Christmas and a very healthy and productive New Year. Take care ,Robert.


    • Robert,

      While some have scoffed that airgunners do not have to know anything about firearms to do some deep learning about the intricacies of accuracy, I’m guessing there are just as many firearm shooters who feel that airgunning offers nothing that can aid accuracy in their guns.

      Edith


    • Robert,

      You just said a mouthful! For example, the 1:14″ twist of a .219 Donaldson Wasp surprises most shooters. But I am having a heck of a time getting a good load for a custom Donaldson that I built with a 1:10″ twist. So sometimes it pays to know what works, before you charge off and try to recreate the world.

      B.B.



  9. Merry Christmas and happy holidays to all!

    The more I review the data on this, the more I think John Whiscombe designed his rifles and the HOTS to have the capability to adjust for three sweet spot of darn near any well fitting pellet. It’s nice that in the same gun you are able to isolate velocity and harmonics separately. I’m looking forward to the HOTS part of the test!

    /Dave


  10. Merry Christmas everyone!

    May ALL the blessings and true message of Jesus enter your being and guide your path…

    May we treat each other with all the kindness and compassion of the blessed One.

    May you always be in Joy.

    May you make the world a better place with each action you take.

    May your Heart sing with overflowing Love.

    May your pellets fly true

    Very interesting results your getting here BB.

    I think they support the theory that each pellet (and even die lot within pellet designs) shoots different at different speeds and in different guns/power plants. You have really opened a huge can of worms here… each segment could start a line of testing. But the main thing I feel most air gunners should get from this is to do lots of testing of pellets at different speeds if you can.

    Again, I sing the praises of the Air Air S400 series with the completely variable power adjuster, and normally a very accurate barrel…. if one is truly interested in finding the “sweetspot” of accuracy for a given pellet in a given barrel/air gun.

    I didn’t notice you saying if the testing was outdoors or indoors. Outdoors would for sure effect results… conditions change hour by hour.

    I’m also assuming that the pellets were not weighed? I’ve found that to really effect results at 25 yards. Some pellets can vary in weight by 10% or so.

    How often did you clean the barrel? After I’ve found a good shooting pellet for one of my bench rest US FTs, and while shooting the 25 meter international Bench Rest target at 25 yards indoors, the cards would be a 249/250 then 245/250, then 230/250.. I would then pull a couple dry patches and collect some lead fragments from the rifling, and after a little “seasoning” of 10-20 shots, the next set of cards are back to 248/250, 250/250, and 249/250.

    Anyway, Merry Christmas!

    Wacky Wayne
    Match Director,
    Ashland Air Rifle Range,
    Hosting the 2012 AAFTA National FT Championships


    • Wayne,

      Good to hear from you again. I have never cleaned any of the barrels of my Whiscombe. The .22 barrel has a couple thousand shots on it and the .177 probably has 1,500 or so.

      All shooting was done indoors, as I wanted to limit the outside influences.

      And I do plan of testing weight-sorted pellets against pellets straight from the tin later on. But next I’m testing the influence of the HOTS.

      B.B.


      • As far as speed goes, about 865fps seems to be where my USFTs like the CPH, Kodiak and JSBs… .177 cal or .22 both like that range for me. I had #27 with the .22cal stainless steel barrel up to 35fpe, but found the accuracy even outdoors in the wind, way better at 26.5fpe with the 16gr Air Arms version of the JSBs.. so that’s where she is at now…. and by the way, that’ with a fill pressure of only 1,200 lbs with a refill after 35 shots at 950 lbs!.. and the spread was 862fps to 871fps.. How’s that for a tight spread with no regulator..

        I’m going to test harmonics next too. Someone told me even a little patch of modeling clay works sometimes.

        Anyway, like Kevin said.. glad to have you back at 100%!

        Blessings to all,

        Wacky Wayne


  11. To B.B., Edith, and all the airgun enthusiasts who celebrate Christmas. May you all have a joyous Christmas and a happy and healthy New Year. All the best.
    Titus


  12. I spent an hour last night pondering before I made my reply.Harmonics IMHO,in the next test phase is going to completely “develop” the conclusions to be drawn from this very ambitious set of tests.I draw this conclusion by observing this fact: John Whiscombe went to unmatched effort to create the ultimate springer.He must have done incredible amounts of testing to create the Whiscombe.The fact that he arrived at a design that employs the HOTS after all that testing certainly suggests it was important.Firsthand experience has shown me that the result range of different settings (of the HOTS) can run from horrible to awesome.Knowing that the pellet used (Premiers,for example) is capable of great accuracy,and that nothing else changes except the point in the barrel’s vibration that the pellet exits….seems to leave room for no other conclusion.This could certainly unlock the mystery of why some springers “like” one pellet over another.Think of each springer of any given model…….variances in part fit,and behavior make each somewhat unique in how they behave when firing.This helps explain why my R9 shoots one pellet best….but yours may shoot another best.It further sheds light on hold sensitivity.I’m very excited BB.I believe you are about to discover the “smoking gun”!!! Merry Christmas everybody!


  13. BB,
    This series has been quite a myth-buster, although I think the results might have been different with a mere mortal springer. Those Beeman devastators have been quite a surprise, to say the least. I must say that I was pretty disappointed to see that they are only made in .177. I hope I am wrong. I have a super hot .25 cal pcp that could use a pellet that works at supersonic speeds.
    I look forward to the next installment.
    Thanks,
    Lloyd


    • Lloyd,

      The Devastator pellet is the result of a many years-long development during which several inferior pellets of the same design were sold by another pellet manufacturer. H&N spent the time and money to do the job right.

      Believe it or not, this is something that cannot simply be scaled up to the next size. The weight and balance of the pellet, as well as the precision of the many die parts is a great factor in the success.

      So far Devastators have met with success and a good reception. I wouldn’t be surprised to see them in .22 caliber next.

      B.B.


      • BB,
        Yes, I understand what you mean about not being able to just scale it up to a larger caliber. The weight would increase at a faster rate than the frontal area. It is nice to see that someone really worked on a different pellet design, and stuck with it until they got it right. A real success story.
        The .22 cal would be nice!
        Lloyd


    • Lloyd,first off,Merry Christmas my friend.Have you tried the new “Kings” in .25?? I just recieved 4 tins.Prelimenary results are very encouraging.I have forgotten that I’m shooting .25! The results so far resemble a good pellet in .22.I have yet to do the noisy testing in transonic & above.If I find good results I will certainly let you know.Been shooting them thru the Condor,still have a couple DAQ’s including one that is really hot to test with.I’ll keep you posted.Oh,I will of course test with the Whiscombe too! I believe it will move them at 750ish.They are very well formed too.


      • Frank, good to hear from you! I have been thru a bunch of the .25 Kings, and am now burning up the H&N Barracudas. I usually shoot over a chrony in my garage, but did get a 58 yd 5 shot group with the .25 Kings of .914″. It was shooting them at about 830fps. Pretty decent for me. BB got me into the Discos and I now have a couple, and one that I have worked over pretty well. Poor thing… it will never be able to shoot leisurely again. They are really fun to work on. Sounds like you enjoy trying different things with your Condor. I am feeling the “need” for one of those more and more, LOL. Some folks find one pellet and sweet spot and set it and forget it. Do you do that, or do you test different combinations a lot? And you say you have a couple of DAQs to try out? I am envious!
        Merry Christmas to everyone!
        Lloyd


        • Lloyd,if you would like to work with one of my .25 DAQs…..consider yourself welcome to borrow one.
          I’m very fortunate…..I can send your choice of pistol,rifle OR carbine in .25.You would be welcome to change/adjust to your hearts content.Winter is a splendid time for the tinkerer.DAQ barrels are capable of great accuracy.
          As for the Condor& Talon…..you can change a whole lot of the character if you have multiple barrels,multiple tanks AND power sources.For example a regged output tank with a Co2 valve alone offers many set ups with different calibers and lengths of barrel.You can swap the tophat assemblies in seconds safely,add an Oring ahead OR behind the tophat rim….I think you get the picture.I could easily spend a year on AF guns alone! So many possibilities,it’s like making a burger.
          To avail yourself of the above offer…..email me.Merry christmas Lloyd.


  14. B.B. and everyone

    Merry Christmas to all of you, who celebrate it on December 25!
    Sorry for being off for quite a time – I had to wage a little personal war and assemble a new computer for myself. Right now it’s win x2 situation and I’m all about tweaking and tuning hardware and software, enjoying J.Strauss.

    B.B., my deepest respect, that is really a great testing. I wonder what would be to put the same pellets through Talon with its adjustable power – to prove or disprove the results for PCP. I think one day it MUST be sold as a hard copy – and there’s a great name for it B.B. ((Blue Book) by B.B. :)

    I made some upgrades to my trusted mod-CFX. I tried to experiment with a higher scope position, feeling it would be more natural to keep my head straight especially since I’m using glasses for shooting.
    Well, I also made some POA/POI compensation job. I bought Leapers dovetail-Picatinny rail with ballistic compensation which they make for RWS rifles. Removed Gamo’s own rail. Then some machining – I must confess I broke my rule (pay for professional’s work, not for mistakes made by your own hands) and worked with my own hands on a milling machine. Problem is that Gamo makes grooves on a cylinder, that are a little bit more than 12 mm and that rail works best with 11.

    So a little touch here and there with 60* “triangular” cutter and I’ve got a nice tight fit. Then comes front recoil “paw” – cut down, make a new sector cut. Then, I’ve got to say some bad words about Leapers stuff – guys, stop using straw-like pins made of unknown steel-like soft clay! make it at least 6mm and of hardened and normalized steel! So I re-drilled and re-сut the thread for M6 headless Allen hardened bold. Then blacken and mount the stuff and voila – I’ve got a new, 18 mm higher mount for my scope.
    It does. It really does, especially for 50m with a cheekpiece given a little 10 mm elevation. First test gave edge-to-edge largest 38 mm group, then, next day I seemed to be getting used to it and shot stable e-t-e 30 mm groups with the best being 23 mm e-t-e. Previous setup could only give me the best of 25 mm. Well, I must train and I think I’ll achieve better groups. Results will follow.

    duskwight


    • duskwight,

      Yes, a Talon SS with a 24-inch barrel will be the next testbed. With the longer barrel I can get a wider range of velocities and the SS will be perfect for this kind of test.

      But before I do that I want to do a couple experiments with the springer first, so no big questions remain before moving on.

      How’s the weather in Moscow?

      B.B.


      • B.B.

        Ambivalent, least to say. It was nice snowy real soft winter yesterday, but today it went zero again, however it’s -4 right now and this jumpy behavior is going to last until the New Year. You can imagine the snow porridge on the pavements – city workers are doing their best, but man must count his odds against nature.
        The worst thing of all is humidity and changing atmosphere pressure. I’m not an old and all sewn-up battle veteran, but I have my number of scars, fractures and a single kinetic energy close experience. This is not pain, I just feel them that they are and it’s a real itch you can’t scratch.
        So if you plan on visiting Russia – I guess you should wait for 3 weeks or so, I hope we’ll get some real winter of -10 with clear skies and shining sun.

        I just can’t get the story out of my head and I would like to hear it if Edith would be glad to tell me – German from Shanghai… You see, I’m writing a book, nothing too serious, pure alt-history dieselpunk fiction about mercenary fighter pillots, so the second part revolves around Southeast Asia and I\m studying the region right now.
        I know that Erich “Divide by 3″ :) Hartmann lived in Changsha before the break of the militarist wars in 1928 and his family was forced to evacuate through Soviet Union. My mercenary pilots are a close followers of Claire Lee Chennault (Claude Louis Chaillot in my story). I’ve read some info on German colony in Shanghai in 30′s but to meet and to be able to talk to the person from my source of inspiration time… Edith, If you don’t mind, please, tell me things you remember about China in that time.

        duskwight


  15. Howdy Mr. B.B. & Ms. Edith,
    First, as a total newbie to the sport & science of air guns, I’d like to thank you for who you are & what you do. As a rookie I don’t even know enough to know what I don’t know! Every one of your articles & comments from “the gang” has something I can learn from. You guys have forgotten more than I’ll ever know & your willingness to share your knowledge & experience has been a big help. Thanx guys.
    B.B., In your 12/20/11 article on the BKL drooper scope mount, you wrote:
    “That made me think of another report I can write — and probably should: What to do with a twitchy breakbarrel. It would be a collection of the tricks and techniques I would use when I encounter a twitchy breakbarrel. In my role as an airgun tester, I see a lot of them over time, so I’ve built up a bag of techniques I employ to deal with them when one comes along.”
    Yes PLEASE! As someone who needs all the help I can get with the basic mechanics of shooting, that would be awesome.
    Again, thanx to everyone here & Merry Christmas.
    Beaz


    • Beaz,

      Welcome to the blog. The twitchy report will be on Monday. I’ve been working on it for many days.

      As for being a beginner, believe me when I say that we are all learning this stuff. I learn from the comments made by the readers, so everybody is equal in this boat.

      I have some firearm blogs planned for next year that I think will fit right in with this kind of report. It will be sort of a Grand Unification Theory when it turns out that firearms and airguns share many things that help improve accuracy.

      B.B.


  16. Merry Christmas and Happy New Year everyone! Please be safe and enjoy your loved ones.

    I’m glad this Part 10 came on a weekend. Lots of extra time to digest and mull it over. This is really going somewhere plus including something we very seldom talk about – harmonics. If this test ends up exposing the sound barrier effects as a myth then I wonder where it came from and why.


    • Chuck,

      I’m not saying that velocity doesn’t affect accuracy, but perhaps it isn’t the chief factor to be considered. Maybe after we peel back the harmonics issue we will find that velocity is a lesser influence than we once thought. But right now it’s too soon to tell.

      B.B.


      • BB,
        Yes, I understand. This harmonics attribute sounds like it’s going to be a tough nut to crack. I’m anxious to see how that plays out.


      • And maybe it is the harmonics generated as the velocity goes up (partly spring and piston motion in some; partly momentum conservation in other guns) that actually affect the release of the pellet. But since those oscillations of the barrel are correlated with muzzle velocity, the easy mistake was to attribute the inaccuracy (if any) to the aerodynamics of a faster pellet rather than the mechanics of the gun.


  17. B.B. & Edith,
    A very Merry Christmas to both of you. Thank you for this blog and the time spent formulating and testing airguns and the related ideas, tools and equipment. This series seems to be breaking some rules we have come accustomed to accepting. It’s perfect!
    I have a un-airgun related question for you, but right up your alley. What reloading manual do you recommend for a complete beginner? I plan on attending the medium range and high angle rifle courses at Thunder Ranch here in Oregon, and am thinking of using my Weatherby Mk V in 300 WM, loaded at less than Magnum pressures. I will need 900-1000 rounds, shooting will be out to 900 yards.
    Any help would be more than appreciated. Thanks again and Happy New Year!


    • Hank,

      I like the Lyman Reloading Manual for one good reason. So many of the other manuals are controlled by the company that publishes them and they have a vested interest in the loads they publish. Like the Hornady manual will never show a load for a Sierra MatchKing bullet, even though they are the gold standard in some calibers. I do read the Hornady manual, but only to get a second opinion sometimes.

      I own an old Lyman manual and have asked Santa for the latest volume for this Christmas because in the old manual none of the recent powders like Lil’ Gun and Tightgroup are listed. But I wouldn’t throw my old manual away, simply because some of those old powders are still the best that have ever been made. Unique that is used in so many loads if well over 100 years old and still going strong. And an older manual will have more of the pertinent loads than a newer one that tries to address modern components.

      B.B.



      • BB, keep in mind that the formula for Unique has changed in the last few years. New lots of this powder are faster burning than the original. They did this to “clean it up” as Unique had a reputation of being a little dirty. Being “hotter”, it burns cleaner. The end result is you have to cut your loads about one grain to get the same result. Example: My old .45 Colt load of 9 grains with a 250 grain bullet needs to go down to 8 grains to stay the same. The old manual data will be based on formulas from the past, not what is currently sold. So, while the old manual is still good, some adjustments need to be made due to changes in currently available powder.

        Mike


        • Mike,

          I did not know the formula was changed. Thanks for that.

          Unique is a dirty burner, but also the most tractable gunpowder made. I have used it in almost every caliber I have loaded, to .45-70. And it is a wonderful target load in the larger centerfire calibers, as long as you remember to settle the powder over the primer before every shot.

          B.B.


  18. What I’m taking away from this test is, barrel vibration may be THE biggest factor and the BOSS or HOTS, if you have it on your gun, may be a real asset. Because the average shooter doesn’t have as many guns as B.B. does, he may have ONE hunting pellet gun, and a bunch of ONE type of pellet, chances are, whatever’s touted as “good for hunting” like Beeman Kodiaks. So he’s going to tune his BOSS/HOTS for the smallest groups with that gun and pellet combination.

    Whereas, yeah, it’d take forever for B.B. to test all the combinations he has!


  19. Merry Christmas from the Enochs to the Gaylords! I got a new shooting hat, a Filson Tin Cloth Bush hat. It’s not a new gun but I like it. I have really enjoyed this series of blogs. I look forward to a PCP test. I thought about a MSP but I don’t think you get high enough velocities with a pumper to do the testing you want.

    Merry Christmas to all of you,

    David Enoch


    • David,

      Like you, we open our gifts on Christmas Eve. It’s a German tradition and Edith comes from German stock.

      Congrats on your new hat. I’ll post my gifts on tomorrow’s blog.

      B.B.


  20. BB

    Quit shaking your presents. You must wait until morning.

    A very Merry Christmas and a Blessed New Year to you, Edith, and the rest of my online friends here on the blog.



  21. A very Merry Christmas to each and every one of you and a special thanks to the Gaylords for all that they’ve done for us last year. It’s a real joy to see the wonderful way you two interact!

    Bruce


  22. It’s 7AM!
    The boys woke us at 5:45. Santa had been, the presents are being played with and the turkey is being readied.
    A Merry Christmas to all…and wishing a great New Year to everyone here.
    B.B. and Edith…may this upcoming year bring happiness and health to you and your family.


  23. I was up at 6!

    And it’s 38 degrees in here!

    Due to freezing/unfreezing garden hose going back here there’s the most amazing stuff in the water, I usually drink the well water blithely but now’s the time for a new Brita filter and filter *everything* not just coffee-water.

    It’s a Spare The Air Day today so I might do some marshmallows on the Coleman.

    I have to make the airport run and I might indulge in the standard pagan Chinese restaurant meal today (although I hope Kuro Ramen is open!) and it’s a great day to do ….. more pellet testing!

    I’ve already got my Xmas present but today I’m now clear to read it …. “Jack Hinson’s One-Man War”, a book that looks like a winner.

    Merry Christmas all!


    • 9:25AM there was 6:25AM here. I actually got a few hours’ more sleep then got up (brr) and got ready to do the airport run for a friend …. Lo and Behold there was the Boone & Crockett Prodigal Possum in the trap, this morning started with a bang.


  24. In reading of accurate BB guns I see the Daisy 499 is the top of the line.

    Can you do a test of its accuracy with the Marriochi that Airguns of Arizona is touting as the most accurate BB gun now? I know PA doesn’t sell it but you write about a lot of air guns. Would love to see reality with your testing and comparison.

    Thanks


    • Daniel,

      I was going to test the Marriochi BB gun for Shotgun News a couple years ago and I think Robert Buchanan steered me away from it. There was some problem with the gun, I think. It’s been so long that I have forgotten why I didn’t test it, but I think I tried to and was directed away.

      B.B.


      • Marzocchi? In any case, I think it’s considered the most accurate smoothbore, there’s a type of I think, 4-H or Scouts shooting that required using BB guns. These are guns that fit the criteria, but give an advantage in accuracy. At least I think that’s how it goes.


  25. BB said, “I did not know the formula was changed. Thanks for that.”

    I’m really glad it helped. I have learned so much here that I want to give a little back when I can.

    Merry Christmas!

    Mike


  26. This series of tests show that accuracy is more complicated than just assuming a simple correlation between velocity and weight. As for harmonics and barrel tuning, that also cannot be simply generalized as a “known solution” to anything but the finest adjustments to a specific configuration. These tests do show that there is a real “sweet spot” for each pellet. However, for each pellet, there are optimal conditions which are unique and not transferable to another pellet/rifle combination.

    What was not really discussed here was the subject of aerodynamics. I believe that aerodynamics are what allow us to arrive at a pellet specific “sweet spot”. The Beeman Devastator was a good example of this. The Eun Jin was another, where poor aerodynamics produced what should have been predictable results (i.e., what can be expected of too long a pellet). I would not be surprised if a more football shaped, but longer bodied, pellet would perform better than the Eun Jin. This pellet would have a smaller skirt, but with a mid-section that allowed for the rifling to spiral the pellet. I don’t know, obviously.

    My point is that there is a great deal more that can go into the design of air-gun pellets. Therefore, if there is one area where tuning is lacking, it is in the design of pellet aerodynamics for specific velocity ranges. This is no different than jet airplanes, where stability issues needed to be solved for supersonic flight. Springer’s introduce vibrations that push the limits of the stability that can be obtained by rifling. Therefore, the big issue is the lack of optimal rifling, but from the perspective of pellets themselves. The ultimate pellet would have the right combination of aerodynamics and rifling traction whereby some amount of self-correction can be obtained within certain limits. No single pellet can provide the answer for all configurations, so pellets need to be produced for velocity range, as well as weight.

    The good news is that pellet manufacturers are far from having solved some fundamental issues, so the industry is still wide open for a better pellet design(s). Someone just needs to be willing to invest in the research necessary to produce better aerodynamics.

    Victor


  27. With regards to an airgunner’s Christmas presents, I will share this story. Last week a coworker mentioned to me his neighbor was selling an old Sheridan and would I maybe be interested. I told him to find out what it was and maybe get a photo. Turns out it was a Model A Supergrade in excellent condition. Still holds air, complete with owners guide and a Sheridan Pellet Trap. This gentleman had bought it new in 1950, and now at age 85, was starting to get rid of a few things. I went to see it on Christmas Eve day and bought it on the spot for a very fair price. My 30 year search is over. Merry Christmas to me!



  28. Not a single air-gun related present in the whole pile! Guess I have to do my own shopping next year.

    But I got a promise that I could go to the eye doc and get a lens made for my right eye. Would be nice to be able to see the front sight again.

    Happy New Year to all!


  29. This is probably not the right forum to raise this question, but I have so far received no reply to my calls and emails from Pyramyd Air….

    The picture of my niece Paysen was selected as Big Shot of the Week earlier in December.
    To date, I have not been contacted, regarding the $50 gift card.
    I would like Paysen to be able to use this card to help her purchase her own airgun (her first).
    Could you give someone a nudge on my behalf?

    Thanks!
    -Joel Cole


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