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Accessories Pellet velocity vs accuracy test: Part 11

Pellet velocity vs accuracy test: Part 11

by B.B. Pelletier

Announcement: Dammion Howard is this week’s winner of Pyramyd Air’s Christmas Big Shot on their facebook page. He’ll receive a $50 Pyramyd AIR gift card plus another $50 in goodies!

Dammion Howard (left) shows off some new airguns he found under the tree this year!

Part 1
Part 2
Part 3
Part 4
Part 5
Part 6
Part 7
Part 8
Part 9
Part 10
Happy New Year from Tom & Edith!
One nice thing about watching a TV program is that it only takes an hour or less to view. You have no sense of the man-weeks of work that go into a short production on screen. Sometimes, the same thing happens in the world of airgun blogs.

I won’t say I’ve been dreading today’s report; but from past experience adjusting the HOTS on the Whiscombe rifle, I knew it might take longer than anyone could imagine to get a good result. It’s easy to say, “Adjust the HOTS for optimum performance with a certain pellet.” Actually doing it is where you discover if it’ll be easy or hard. The report I have for you today was very hard.

I allotted several hours to the actual testing and adjusting that would have to be done. And with my past experience with the Whiscombe, I knew shortcuts the average shooter wouldn’t think of. Let me lay the groundwork so you understand what’s happening in this process

The Whiscombe harmonic optimized tuning system (HOTS) consists of a weight that can be adjusted in or out along the axis of the bore. A jacket around the barrel is threaded to receive this weight. The threads on the weight are very fine, and one turn of the weight moves it a millimeter in either direction. One complete turn of the weight constitutes 1mm movement of the weight.

Besides the weight, there are two other metal parts. One is a short collar that locks the weight in position after it’s been adjusted, and the other is a much longer cover that encloses the entire HOTS from sight. This longer cap doesn’t need to be removed from the weight to make adjustments, just provide access room for the special wrench that moves the weight.

Here you see the HOTS mechanism. The threaded weight is turned in or out of the barrel jacket by the wrench. Once the weight is where you want it, lock it down with the knurled collar on the barrel jacket. Then, install the long cap, and the job is done.

Where to start?
The problem is always the same: Where do you start adjusting the weight? The simplest way is to start right where you are — with the HOTS in the last position it was set. Shoot a group at that setting and go from there. I had that data, of course, from the earlier part of this test, so that’s where I began. Because the last transfer port is still installed in the rifle, the Beeman Devastator pellet still develops about 772 f.p.s.

When I shot a group at this velocity in the earlier test, 10 shots went into a group measuring 1.073 inches between centers. I was looking for a group somewhere near that size this time, too. It might be a little smaller or larger; but if it was a quarter-inch group, there was a problem with the results of the last test. The same care was taken with each shot; to do any less would have skewed the results or made them unreliable at the very least.

The first group shot in this test, shot with the same HOTS setting, measured 0.953 inches between centers. That’s 0.12 inches smaller than the group from the last test. I would call that in the same ballpark and therefore a confirmation that the last test was sound.

Ten Beeman Devastators at 25 yards went into this 0.953-inch group with the original HOTS setting. It’s close to what the gun did in the last test on the same setting.

Adjusting the HOTS
Whiscombe says that there will be several sweet spots throughout a one-inch movement of the weight, which is approximately 25 full turns. He also says that one spot will be better than the others, and that’s the one to look for. He just doesn’t tell you how to find it, other than by adjusting the weight one turn at a time. But my experience told me that the sweet spot was probably not where the weight was at this time, so I turned it in (toward the receiver of the gun) four full turns and shot a second group. This is where my experience with the Whiscombe was supposed to pay off.

I wasn’t going to waste my time shooting 10 shots if the first 5 were spread out. Why bother? I wanted a tight group, and if inside 3-4 shots — or even 2, on one occasion — there was already a large separation, it was no use going further. I turned the weight in 4 full turns and shot another group. This group teased me with the first 5 shots in less than a quarter-inch, but the final 5 expanded that to 0.977 inches. Can’t be certain because of measurement errors, but no improvement at all.

At 0.977 inches, this group is slightly larger than the original setting. Obviously, the HOTS isn’t adjusted at this spot.

Next, I tried the weight 5 turns in from the start point. The group was worse. I backed out to 3 turns in and got about the same size group as with 4 turns in.

At this point, I experimented with some subtle adjustments on a half and then a quarter turn. At 3.5 turns in, I got a group that was slightly smaller than the one at 4 turns, but it had one called flyer. I tried another quarter turn in and got 4 shots in a group measuring 0.998 inches between centers. Obviously, I wasn’t going the right way.

No sense finishing this group. Four shots are already grouping 0.998 inches.

Okay, this wasn’t working. I adjusted the weight out in the other direction 9 full turns past the initial setting and shot another group of 10. This time there was some success, as the group measured 0.794 inches between centers. I wanted to call that the end of the test; but looking at the group, I knew it wasn’t enough of a difference to impress anyone. Even though it does show improvement over the baseline group, I would like to show a larger change since one of the Devastator groups in the earlier tests measured 0.616 inches. This group was too much larger than that. The gun should be able to do better if harmonics and not velocity was the main driving force behind accuracy.

This group is better than the baseline group, but it’s not as good as some groups that were fired in the big test. It measures 0.794 inches between centers.

By this time, I’d fired 49 shots in about 90 minutes. The test work had lasted much longer than expected, and I had to quit for the day.

A happy accident
The next morning, I was back at the bench and trying to complete the work. I figured I would adjust the weight out from the initial setting by a certain amount but as I tried to do that a happy accident happened. The front cover got stuck together with the weight; and by the time I noticed it, I’d already adjusted it 15-20 turns. Except, I had no way of knowing how many turns it was. I had to start all over, and this time from a random place that bore no known relation to the initial start point. Not that it mattered, except I didn’t want to waste all of the work from the day before.

I adjusted the weight at a point that looked to be well away from the initial setting. Then, I shot a group as a baseline. Or I should say I began to shoot a group. After 3 shots, I had a spread of 1.153 inches between centers — the largest spread of the entire test to this point. No sense finishing that one!

Past experience has shown that the sweet spots are often a couple turns in either direction. I guessed and turned the weight back in three turns from the starting point. And that was when it happened. The clouds rolled back, the angles sang and the rifle grouped like I knew it could. Ten shots went into 0.523 inches. That’s not only the best group of this little experiment with the HOTS, it also beats every group fired with the rifle during the main test conducted earlier.

This group of 10 was shot on the second day, with 3 turns in from the start point. It measures 0.523 inches and proves that the Beeman Devastator can shoot accurately at 772 f.p.s.

The results
With this kind of data in hand, I can say with some confidence that harmonics and not velocity is the main driver in how accurate a spring gun can be. I say this because the worst group shot during the velocity test was adjusted harmonically into the best group of the test with this pellet. There’s no chance in this group — it’s clearly much better than it was in the beginning.

Could the rifle shoot this pellet even better? Maybe. But it isn’t necessary to prove the point we were trying to prove.

Next, I want to adjust the rifle for Beeman Kodiaks at a higher velocity and test pellets straight from the tin against pellets that are sorted by weight. Today’s report should give everyone the confidence that, if a difference in accuracy is noted, it will be because of the pellets and not the gun.

author avatar
Tom Gaylord (B.B. Pelletier)
Tom Gaylord, also known as B.B. Pelletier, provides expert insights to airgunners all over the world on behalf of Pyramyd AIR. He has earned the title The Godfather of Airguns™ for his contributions to the industry, spending many years with AirForce Airguns and starting magazines dedicated to the sport such as Airgun Illustrated.

92 thoughts on “Pellet velocity vs accuracy test: Part 11”

  1. Have I ever got the HOTS for a rifle like that!

    The testing looks a bit tedious, but worth it. People buy lots of tins of pellets to get that improvement in groups and the HOTs enables you to, theoretically, tune for good groups with almost any pellet.

  2. B.B.

    Well, looks like you have given us a good indication that vibrations influence accuracy. It goes a long way towards explaining why group size did not change in a logical fashion with all pellets if speed were the only factor. I would suspect that if you jacked the velocity back up on the Devastators that the accuracy would fall apart. Might or might not happen though. If you could change velocity gradually you might see accuracy coming and going as the velocity is varied across the spectrum.

    On weight sorting the Kodiaks (after adjustment) you may or may not see a difference. I have seen some pellets in some rifles not make any noticeable difference in chrono strings when sorted unless there were a few odd ones that were damaged or at the ends of the sort spectrum.
    Then there are other rifles that show a noticeable difference in velocity when sorted pellets are used. So how much difference will it make in the groups? Could depend on how touchy the rifle is about getting the pellet out of the barrel at a null vibration point or at least a consistent vibration point.

    So looking at things, we may find that speed as it relates the combination of drag and gyroscopic stabilization may have the most effect on accuracy down range as the relationship changes. So at what distance does any particular pellet start to fall apart when fired at a particular velocity?
    We don’t even want to get into what the wind is going to do.


    • twotalon,

      I know that I’m risking failure with weight-sorting the Kodiaks, since they already shoot so well. But this is the kind of stuff we all talk about, so I think it has to be done, anyway. Let the chips fall where they may!

      As far as downrange performance, a man could spend his life trying to make sense of it unless he concentrated on one pellet. Then it becomes very straightforward empirical testing, once all the other variables have been eliminated.


  3. Wow so much to catch up on after being offline for a week BB.

    Firstly not much in the way of air gun gear for me this Christmas.In fact not a much in the way of any gear to be honest.lol
    All the kids had a great time though so that’s the main thing.
    Hope you all had a great one and wishing you the very best for the new year.

  4. Well, this is bad news – very bad news! I have some good springer rifles and one is pretty accurate but not a single one with a HOTS adjustment. I feel discouraged now because, even though I may reach very accurate with more practice on one of these, I’ll not be able to reach very, very accurate without a HOTS adjustment. In the words of Babu on a Seinfeld episode: “Thees ees a bad blog, a velly bad blog!” (well, you really have to hear it said with Babu’s East Indian accent). 🙂

  5. BB,

    What an amazing report. Not only did the harmonics change the size of the group, the HOTS adjustments changed the POI significantly between settings too.

    You consistently raise points that most of us wouldn’t know to check. Thanks for letting all of us what over your shoulder as you experiment. Little wonder that so many of us anxiously wait for the next article!


    • Herb,

      Yes, the POI did change significantly when I adjusted the HOTS. But I also had to adjust the scope sometimes, as the HOTS had the gun grouping two inches below the point of aim.

      I decided to not mention all of that, since it didn’t help the report and might confuse some readers.


      • During the course of this series I mentioned my experience with a vortek adjustable muzzle brake so bear with me while I repeat myself. I shot at 30 yards. Never saw a consistent, measurable shrinking of groups but poi changed dramatically. Because of this experience I know that harmonics in an airgun affect the pellet.

        I’m sure that if I would have shot at longer distances in a wind tunnel that change in group sizes would have been more significant and relevant. I also believe that a tuning device whether it’s a hots, boss, vortek, custom ? or limbsaver won’t turn an inaccurate gun into an accurate gun.

        IMHO we’re in very advanced airgunning territory. There are so many things to try prior to a harmonic tuning device before you know what the ultimate, potential accuracy of your airgun really is. Personally, I don’t think airgunners spend enough time with their new airgun experimenting on the hold that gun wants. I don’t think the average airgunner spends enough time testing a variety of pellets. It amazes me that so many airgunners sell their wonderful guns because it won’t shoot THEIR favorite pellet! Find the guns favorite pellet and ignore your personal preferences and prejudices. I read about this regularly….”If a gun won’t shoot pellet A or B I sell it.” IMHO these folks are missing out on some really great guns since they don’t want to stock up on pellet C. For crying out loud cost of quality pellets is the cheapest part of this hobby and makes the most differance in relation to cost. Cheap cost of ammo is among the primary reasons everyone gets hooked on airguns.

        Wow, didn’t know I had a pent up rant inside me this morning. Sorry.

        A Happy and Prosperous New Year to everyone.


        • Kevin,

          You are so right-on about figuring out the fundamentals of shooting with a particular air-gun first. I have seen my groups shrink from over an inch to almost a single hole at 10 meters with almost all of my air-rifles, after a lot of refinement of the fundamentals.

          For the most part, I stick with the light CP’s that I can buy at Walmart. In .177 caliber, some guns hate the lights, but love the heavies that I buy from PA, and visa-versa. Getting that almost single hole 10 shot group at 10-meters is a huge source of gratification and sense of accomplishment. For my FWB I use high-end competition pellets, but that’s an entirely different purpose, so I don’t usually talk about that much.

          My real hobby is with springer’s (the kinds that people can buy almost anywhere). That’s where I find the most interesting challenges and rewards. Possibly different from most, I tend to stay the longest with the gun that causes me the most trouble. In the beginning, that was the case with all of my springer’s. I tend to move on from a gun after I’ve shot that super-tight 10 shot group.

          The only exception, as far as pellet selection goes, is my Gamo Hunter Extreme in .22 caliber. I buy JSB Exacts Jumbo Heavies for that gun. That’s my go to gun for 50 yards and beyond. The only issues that I’ve had with that gun are with screws (mostly scopes but also the stock). It’s got a hard kick, so I have to monitor the screws. I did have to send two scopes, that ship with the rifle, back for replacement because they simply broke.

          In any case, with a lot of dedication and hard work, I’ve gotten incredible accuracy out of my springer’s, with the only real adjustment being whether I used light or heavy pellets. And yes, pellets are cheap.


  6. B.B.,
    So what exactly does a poorly tuned gun do to the pellet that would cause groups to change?

    1. Is the barrel pointing differently at the moment the pellet exists for each shot?

    2. Is the vibration of the overall system affecting the hold, causing random, inconsistent, jumps that the shooter simply cannot overcome?

    3. Is there an affect that remains in the pellets motion after it leaves the barrel, including while it is in flight? The last thing comes to mind when I think about the video that shows how pellets can fly in circular patterns, as opposed to straight parabolic arcs.

    I know that some small-bore shooters are using tuners for competition, but such tuning only works for a fixed distance. I believe that a similar effect occurs by cutting the barrel length to match a particular velocity to range.

    So what does this tell the rest of us who have “ordinary” off-the-shelf springer’s? Is there a way to tune those with something that might be attached to the barrel. I’d imagine that something could be designed to install on top of most barrels (similar to the dovetail adaptoer mounts that you can add to certain air guns) that could possibly affect barrel harmonics to some point.


    • Victor,

      When you adjust the HOTS you move the muzzle of the rifle to the nexus or crossover point of the vibration sine wave. So when the pellet leaves the muzzle the muzzle is the part of the barrel that isn’t moving.

      It doesn’t affect the hold, but like Kevin mentioned, the hold needs to be as perfect as it can be to get the most from tuning the harmonics.

      A pneumatic also vibrates, but far, far less than a springer. So it acts much more neutral, which is why pneumatics are easier to shoot accurately.


      • BB,

        I think this was extremely good science. Like most good experiments, and particularly most improvements in measurement accuracy, it will open a door to a myriad of new questions, so don’t think you’re finished yet.

        As I think about it, I’m sure that the HOTS (or any similar system) doesn’t put the *displacement* nodal point of the barrel at zero. What I think is zeroed is the velocity of the muzzle. My guess is that’s what you were saying when you responded to Victor. I see that a fair number of bloop-tube/tuner combinations are being sold to small bore competitors on the international scene, so it would seem they believe the tuner makes a difference to their scores, or makes it easier for them to shoot high scores repeatedly. Probably true that the same is true for air guns, even if the oscillations from a PCP rifle are rather smaller than for a free rifle.

        Now another question arises: what effect does hold have on harmonics and “HOTS” (or equivalent) tuning? Depending on how the barrel is bedded and the gun held, it could make a lot or a little.

        And does the tune change depending on the mass of the pellet, or even on the design of the pellet? I think it might, meaning that you might have to back off or add in a half turn or so to get to optimum if you change pellets.


        • Speak of tuners… and there’s new stuff :

          Joined: 22 Apr 2010
          Posts: 127

          Posted: Thu Dec 22, 2011 1:49 pm Post subject: Nice looking new gear!
          Hi Everyone,

          Has anyone here tried out this new tuner tube?



        • Pete,

          The harmonics do change when the pellet is changed. So the answer to your question about the weight of the pellet, relative to the “tune” is yes, it does change. The HOTS must be adjusted for every pellet and for every velocity of a given pellet.


          • B.B.,
            This was going to be my next question after your response. So this implies that once you’ve figured out how to tune for a particular pellet of a particular weight, then further improvement might be found by selecting a better pellet of that same weight?

      • When you adjust the HOTS you move the muzzle of the rifle to the nexus or crossover point of the vibration sine wave. So when the pellet leaves the muzzle the muzzle is the part of the barrel that isn’t moving.

        Which also contributes to the change in POI, as the point where the muzzle is moving least is at the extremes of flex, when it is changing from moving outward to moving inward. Imagine a pendulum clock — the pendulum “stops” at the end of each swing, and is moving fastest at the middle of the swing. If you now visualize a pellet dropping down the pendulum shaft, a millisecond difference in leaving at the middle of the swing has a great effect on where the pellet is going — but a millisecond at the ends of the swing has minimal change in final direction.

        Of course, a barrel may be vibrating in a Lissajous pattern, so one has “windage” and “elevation” frequencies to map out — hypothetically one might create a wide but flat pattern if they’ve mapped the vertical frequency (pellet always leaves when the barrel is at top or bottom) but not yet canceled the horizontal frequency…

      • Chuck,

        I think any thing you do to a gun will affect its harmonics. Just as you get a different sound from a guitar string as it ages and builds up a fine layer of corrosion, dead skin, etc, along with stretching, out changes its tone over time. Where the string is plucked in relation to the bridge and different weights of strings cause different sub-tones (sub-sine waves) that are discernable.

        On a gun, those different waves will cause a change in the poi, and group size. Also playing in to this is the consistency of the ammo. Ammo that has large variances in its manufacture will have relatively large variances in velocity. This causes a slight difference in the position of the vibrating barrel when the projectile exits, which in turn causes a different poi. Moving the scope on a gun will cause a slightly different vibration pattern to develop. The reason we can see the effect of this difference is the long distances we are shooting.

        You probably already knew ask this…. Just posting for anyone who didn’t.


      • Chuck,

        I agree with Dave. If changing the pellet weight, as B.B. mentioned, requires re-tuning, then probably anything that you do on the gun will have some effect. However, since the scope is mounted behind the barrel, it’s effect might be different than what we can tune-out with a barrel tuner.


  7. B.B., regarding what you wrote regarding open sights, I want to ask you to write a few words about “Quigley” and the Sharps rifle and the shooting in the movie.
    I hate to write and run, but I must keep an appointment with a neurosurgeon regarding my deteriorating cervical vertebrae. The saddest part is that I just picked up my Hatsan 70 after several years and bought a new rifle as well. If I must have surgery, I already know it will be another 6 months before I can seriously think about picking them up.
    I expect I will be learning a great deal from you and others.


    • kenholmz,

      I’m sorry to hear of your impending surgery, and I know what a bummer it is to have guns that you can’t shoot. But things do get better and as time passes the bad stuff tends to fade.

      I would enjoy addressing Quigley and what is in the movie. I love that movie, and talk about it with my shooting friends all the time.

      Perhaps the best way to discuss Quigley would be to relate the movie to the real world, in the form of the Creedmore matches and Wimbleton.

      I need to try to relate what I say to airgunning, so give me some time to ponder it.


      • B.B.,
        Thanks for offering a bit of hope for the future.
        As for Quigley, I did cheat a bit. I have read you profile info so I know you like the movie (except for the shooting) and I have read enough to know that you understand the shooting. I have just used your post about iron sights as an excuse to ask you about it. Of course, I do hope you will be able to write something about it but I will also understand if you don’t. I haven’t watched Quigley in a couple of years so I pulled the DVD out. I would ask you about Jessie Stone (Tom Selleck just keeps getting better with age), but I don’t know how we’d work airguns into that discussion.

        I wish you continued health and a great new year,

    • Kenholmz,

      Be careful before you have a cervical fusion. My last one went very badly wrong. My first one went spectacularly right. Talk to the surgeon about consequences for shooting in particular, for example neck mobility and flexibility, and how your cheek and your stock will get along after recovery. And don’t really believe the nonsense that you’ll never notice the tiny loss of movement.


      • Pete,
        I appreciate your comments. What you mention is the very reason I elected to have a round of traction therapy first. However, I have seen the pictures and I may not have a lot of choices. I was especially discomfited when I learned the surgery would have to be done through the front of my neck (to one side or the other of my trachea).
        I do hope you are doing better (or that you do get better before long).

        Best to you,

  8. I will stay away from reiterating what has already been discussed above for the sake of brevity.I will instead remark about how wonderful and reassuring it is to read the honesty in your words.Precious few folks are willing to write without the facade of already knowing everything,and just teaching the rest of us.Your experience with the HOTS mirrors mine,except that I would have never thought to leave the “cap” on when adjusting and just thread it out enough to provide access.Adjusting it is an excellent test for Attention Defecit Disorder.I laughed at myself reading this,because I also had the weight move an unknown amount when removing the cap piece!You have built my confidence to tackle tuning the two barrels that aren’t where I need them to be.I will be engraving fine lines as witness marks before I change the ones that are shooting really well.I plan to number any mark I make and then record on paper which pellet the mark refers to.Then I will laminate it to keep in the case
    for future reference.I KNOW the next owner will really appreciate it!After reading this blog,hopefully people will understand more when they read some of the comments made elsewhere about “I just bought a Whiscombe……but it’s not very accurate” ….sorting one out and getting used to it takes time,but is VERY worth it!

    • Frank,

      You have admirable intentions and blame it on ADD. I admire those airgunners that keep a page on each gun they own (typically in a 3 ring binder). The details of what was done to the gun (full tune by _______ or home tune with ________parts), when it was done, velocity/chrony results and when they were taken and with what pellet, serial no., etc., etc.

      HOWEVER, I’ve learned through buying a new/used airgun that “best pellet” may or may not apply to the gun when it gets to my elevation (5,200 feet) and when I sell an airgun my best pellet at 5,200 feet elevation may not be the best at the buyers lower elevation.

      I suspect the same may be true for information gathered regarding the hots system unless your buyer is at a similar elevation to yours.

      Happy New Year Frank. Hope this next year treats you like the gentleman you are.


      • How stupid I feel! It has simply never occurred to me how air density might skew my results to the point of uselessness.That begs the question…..John Whiscombe set up HOTS barrels for boxed Premiers for the original purchaser.I wonder if he ran into that issue? In my head I’m not certain if the opposed piston system is equally effected.I’m sure velocity would suffer some percentage of loss,and as a function of that the exit point of the pellet has to change.It seems like something very interesting to explore further! Is the inertia cancelling effect of opposing matched pistons variable in effect when the air compressed between them is less dense? And further,do the vibratios change frequency too,or only the pellet’s velocity and therefore said pellet’s exit of muzzel?? Wouldn’t it be neat if the vibration change AND velocity change ran parralell resulting in NO change in group size!?
        Well anyway……Kevin and all;May this year we’re about to start be the best one yet!! Happy New Year!

        • Frank B,

          You’ve asked some very good questions regarding potential differances of shooting a Whiscombe with a HOTS system at dramatically different elevations. To my knowledge no one has ever done any testing at dramatically different elevations with a Whiscombe.

          Seems a logical step in this series for B.B. and Edith to come to Colorado with the Whiscombe and conduct these necessary tests to obtain these critical answers. I think the cats would enjoy a change of scenery too. I’ve got guest quarters, pellets, shooting benches, a chrony, etc. I’ll take one for the team and volunteer to aid in this testing with the Whiscombe! I also think it would be wise to conduct some shooting tests with the Ballard at this elevation so that could be done as well.


  9. I took my grandson Nicky to the range again today. He was shooting one of my Daisy 880’s (the Chinese made one).

    A couple of the powder-burning guys were shooting at playing-card size targets on the 100-yard range.
    One invited Nicky to try it with a .22 auto rifle with a “shoot all day” banana clip. After three shots, he was hitting!

    Meanwhile, I tried with my Storm XT. I was getting my pellets down there, but couldn’t hit anything.


  10. Can’t believe it… Crosman is launching the 1322, finally. My wife just jumped through many hoops to find me a 2289 Backpacker for Christmas (not very different from a 1322 with shoulder stock). Well, she got it and it’s amazingly nice. I’m happy to see the 1322 officially launched though, as I know many people were essentially building them from a 1377. I have to say though, I think the grips on the Backpacker are superior – they’re wider and offer a better grip with fewer pinched fingers in the pump. I also like the tool less ability to take the stock on and off, great. I’m not a fan of the front sight, that fiber optic is fragile, and while the Backpacker easily takes down for placing it in one’s backpack, the front sight is exposed. I may have to replace that with something more durable (Suggestions?). Yup, it’s a backpacker and going backpacking. The weather was warm today, and I was able to go outside and sight it in. It was a pure joy to shoot, love it.

    Question: The Backpacker came from Canada, where they are limited to 500fps. There is a valve with an air bleed off hole in it to keep the power down to Canadian regulations. I’d like to either plug that bleed hole or replace the valve with a US model so that I can shoot at full power (I’m in the states). Can anyone provide instructions (or a link to them) on how to get to that valve and replace it. What is the US valve part number? Thanks in advance for any and all help, it is very appreciated.

      • Yup, that’s how I found it. I don’t have the heart to show my wife, not after all the looking she did to find a 2289 for me for Christmas – a NIB one no less. All that trouble would have been unnecessary if I knew this was coming out. I’m glad I have the Backpacker, I’d still prefer it over the 1322 but getting the 1322 would’ve been easier.

        • Bristolview

          Don’t fret, the 2289 is far better than having a 1322 IMHO. All of the modding to my 1377 was done to make it into a 2289 ( with metal breech and 18 inch barrel. ) The forearm of the 2289 is an ergonomic pleasure in the hand, while the 13xx forearm is chafing to put it mildly.

          • I’m not fretting, just surprised. Had the 1322 been available when I was looking, I likely would have gone that route. I looked into building one, starting with a 1377 – crooked barn quoted it for me since I don’t know how to do it myself. I agree though, the Backpacker is much nicer. A friend has the 1377, and the backpacker grips are way nicer to use. I’m very happy with it, now just need to replace that valve with the bleed hole.

      • It’s about time, Crosman! I’ve had mine since the early 80’s, and it has just recently shown signs of needing a rebuild! My Medalist has ben one of my all time favorites!


  11. I am overwhelmed…

    I watched “Infested” on Animal Planet last night for lack of anything better to do. Holy crap !!!!!
    Coons, bats, rats, and cockroaches!!!! Had no idea that houses could be infested that bad. Incredible herds of vermin. I will never complain about not having enough vermin to keep me entertained again.


    • TT, Being new here, still tryin’ ta learn the lingo. “Coons, bats, rats, and cockroaches!!!! Had no idea that houses could be infested that bad. Incredible herds of vermin. I will never complain about not having enough vermin to keep me entertained again.” Is that how “The Gang” here refers to the anti gun crowd, or do you mean the real ones? I’m new & I’m learnin’, thanx for your help…? Happy New Year.

    • I could seriously be a real-life Dale Gribble, I think being an exterminator could be fun! But, what scares me off is, the drama that goes along with the kind of neglect that results in …. calling the exterminator. That, I don’t like.

  12. My wife (blonde) just bought a WII. Waste of money. Unless….
    Are there any good hunting video games out there for this piece of junk? Something along the “flavor” lines as Grand Theft Auto 4 ? Blood and gore. Points for any and all law violations. Lose points for legal hunting practices. Destruction on par with the real life weapons on real life game. Able to gut game. Must include a big spray can of gut pile scent.

    If I can get something like that, then this thing may have some redeeming value.


    • TT,

      I got a Wii for Xmas several years ago, and we love it. We use it to entertain our family during our regular Christmas and Christmas in July gatherings in our home. My brother liked it so much that he got his own Wii this Xmas. He invited a neighbor to come over & play some golf, and they both love it…and now the neighbor is going to get one.

      While we like lots of guns & explosions in the movies we watch, we’ve found the Wii to be tons of fun even though there are no explosions or guns in our games 🙂

      There are Wii games that have blood, guts & gore. I strongly urge you to read all the reviews on Amazon and even look at the YouTube videos of the games you’re considering before buying any of them. I’ve avoided some real dogs.


      • Edith……………..

        I tried a few computer video games a long time ago, but never really got into it.
        I did hack a couple of them. I messed up a version of Space Invaders. Changed the parameters on the bombs they were dropping so they stopped just short of hitting me. I could go get a beer and let the game run. Then come back and blast them left and right in complete safety.

        Then there was one that was the same thing as Demon Attack. Changed the wrong parameters and the game started out about 10 levels worse than I had ever gotten to. Talk about losing fast.


      • I do volunteer work with stroke survivors and we have them use the Wii. Just about all of them have lost the use of one arm so the Wii in the good hand gives them a lot of fun and helps them rebuild coordination. It’s good therapy. Usually the bowling game is what they choose. The females also like the exercise/dance “games”. Shameless plug – I’m building our stroke camp blog site if you know anyone who has had a stroke: rrscb.blogspot.com . It’s still a work in progress so forgive any typos.

      • Fun with blondes…

        O.K. The Wii worked O.K. as far as the blonde could tell until she tried to load the game. No workee.
        So what’s bad? The disk or the unit? Only have one disk, and don’t know anybody who has one so we can borrow a disk and figure out what is going to be taken back to Chinese-Mart.
        So I go out and buy another game so we can figure this out.

        Got home and went to switch disks. Strange thing….the box has little feet on the top, and the writing by the buttons is all upside down. I eject the original disk and find that the label side is up. Things are looking really suspicious at this point.

        I install the new disk label side DOWN, and surprise, surprise!!!! It works. Did the same with the original game disk and it works now.

        Does a Nintendo cause brain damage as soon as you touch it ? She has played other Nintendos before (the old ones that used a cartrige). They called them “tapes”, even though there is no tape in them. I tried to prove this to one of the neighborhood Nintendo numbskulls one time by opening up a cart and showing him that there was NO TAPE…..just a big memory chip. He insisted that the chip had a tiny tape in it. Brain damage.

        I am going to stay away from the thing.


        • twotalon

          For what it is worth, the phenomena is not limited to blondes.

          Best you stay away from that video game console. I have a Playstation 3, and vast stretches of time disappear on me. Brain damage.

          Then again, blasting everything in sight into tiny pieces with an ever-changing arsenal of weapons is quite cathartic. Maybe check out any of the Call of Duty games. The Modern Warfare editions are the best, Black Ops is good too.

  13. My name is cowboystar dad and I am an airgunalcholic!!
    It’s been awhile since I’ve been able to get out shooting with the boys…winter ya know!!
    So I got it in my head that today would be good day to go out…the weather has been mild, right around the freezing mark. The winds were forecast for about 15mph…not ideal, but not bad either.
    Well, I got up at 6AM and checked the weather. 15F (well below freezing) with a steady wind of 20mph gusting to 40mph with the occasional gut to 50.
    Hey…we’re tough, we’ll give it a try.
    So out the door by 7:30AM and a quick stop at McDonalds and we’re on our way (the range is a 40 minute drive).
    Well, hell…with the wind this was a total mistake.
    The wind was actually blowing over the chairs at the shooting station if you weren’t sitting in them.
    Within minutes, although we were warmly dressed it was near impossible to pick up pellets because our fingers were numb.
    The boy (being smarter than their dad) sat in the car and played with their Nintendo DS’s.
    But I persevered…and in truth was very pleased.
    I got a couple of 10 shot groups that measured under 1.5″…with 40mph gusts!!!
    I came away with 3 thoughts:
    1. the JSP Exact RS is going to be THE pellet for this gun (the Slavia).
    2. new admiration for the people I’ve met who were snipers in Afghanistan…I can’t imagine sitting
    out in this weather for hours on end waiting for ‘the’ shot.
    3. I’m nuts!!!

  14. Tom, Edith and everyone on this blog –

    Happy New Year, may it be way better than 2011!
    And special wish for all of us – may our pellets fly straight, may our aim be right and may our guns be ok and crack only for our fun and our meal, amen.


  15. Happy New Year to B.B., Edith,and all the airgun fraternity. I wish you all much happiness and health for 2012. And don’t worry about the end according to the Aztec calendar. They didn’t evan predict the coming of their own demise at the hands of the Spanish.

    • Titus,
      I believe the their calendar really extends farther out but what I think happened is they ran out of paper trying to print the whole calendar so they just had quit printing at Dec 21, 2012.

    • Wasn’t that the Mayan calendar? Rather than the end of the world, some say that the Mayan calendar says it’s time for change. So go to Staples and get a new Mayan calendar and it would be good for another 3,000 years.
      Our calendar runs out every year. Has the world ended yet?


      • Hello Twotalon. I believe you are correct. The Mayan calendar is the one that people are using for reasons of their own. The Aztecs where in the place we now call Mexico. Either way, the Spanish plundered and pillaged both civilizations for the gold that was needed to fight the myriad of wars back in Europe. My, how history repeats.

        • I have watched a lot of TV and have seen a lot of stuff on what they figure happened with some of these previous civilizations. They have no idea what happened to some of them. Interesting stuff, but a lot of speculation most of the time. No doubt the Spaniards did in some of them. Some of the others did in each other. Since the days of early man, it is always the same story. We are supposed to be the most advanced and superior species. Is this what is called an oxymoron? Or just a bad joke?


  16. The next morning, I was back at the bench and trying to complete the work. I figured I would adjust the weight out from the initial setting by a certain amount but as I tried to do that a happy accident happened. The front cover got stuck together with the weight; and by the time I noticed it, I’d already adjusted it 15-20 turns. Except, I had no way of knowing how many turns it was. I had to start all over, and this time from a random place that bore no known relation to the initial start point. Not that it mattered, except I didn’t want to waste all of the work from the day before.

    Nice to know the Browning BOSS has one advantage <G> The micrometer gradations that allow one to easily reset the distance. {Now all I need is money and a range day to fiddle with the one on my A-bolt II .308Win Varmint gun — along with taking all the airguns to a range to continue the scope sighting… Guess it’s time to google ranges in Grand Rapids}

  17. Hi Tom, I recently read your piece “Are We Finished?” Very impressive! I like the way you applied the scientific method. I like your ability to question, and to see where improvements need to be made. There is a lot more ground waiting to be covered. Good science and applied art will help us go farther down that road.



  18. If you want a regression model done on your data let me know. This will quantify the influence of velocity and vibration settings on the same pellet across a range of settings on both.

  19. I have an RWS model 48 with a Vortek spring kit (with top hat), Vortek piston seal and Vortek breech seal. I have home tuned the trigger, buttoned the piston and honed the piston tube. It has been properly lubricated with Maccari super lube and the spring was not overwhelmed with tar, just a light lube with molly paste.

    The Vortek spring has 2 turns cut off of it and both ends highly polished.

    I also have a TX200 with a Vortek spring kit that I highly polished the spring ends, and did the same lube job as the RWS 48 on.

    The Tx averages 860FPS with H&N field target trophies and the RWS runs at 825 with the same pellets.

    Both guns measure 3 1/2 inches from the piston tube to the pellet port when cocked so the piston travel seems to be about the same for both guns.

    Question is as follows:

    Why does the RWS seem to have much more recoil and snap during the shot? The TX is more accurate and less hold sensitive but not by a whole lot. It doesn’t seem to recoil as much either.

    I could understand this if the RWS was right out of the box but it has been worked over with a lot of TLC. I did make it considerably better but even with similar specs to the TX, the RWS still has a way to go. Yes, I have tried a variety of pellets and pellet weights.

    Can you suggest why the two rifles have such a different personality even though the RWS was de-tuned from the higher power it came out of the box with.

    • Bob R.,

      I will be guessing about this. The TX piston is so much more refined than the Diana (RWS is just the exporter) piston. Honing the spring tube was a nice touch, as was buttoning the piston, but Air Arms did everything right from the start.

      Perhaps the most important thing about the TX is its central transfer port. It allows the gun to maximize power without a lot of effort. Guns with offset ports like the Diana have to work much harder to achieve the same performance.

      Those are my guesses.


      • I’d probably add a few other potentials: mass of the piston relative to the total mass of the gun; and partly related to the port you mention — height of bore relative to shoulder contact point.

  20. I think the central transfer port in the 48 is not offset. It is dead center in the piston tube (if that is what you mean).

    The gun itself is quite heavy, 8.3 pounds for the 48 vs. 9.3 for the TX. That pound could make a difference when it comes to spring guns, I agree.

    The mass of the piston makes a lot of sense. The 48 is close to a magnum rifle and I think the piston is a bit heavier. I will explore that when the guns are apart.

    Thanks for the replies

  21. Would you know what a good scope is for my pellet gun it has a dovetail mount but all the scopes i have used become inaccurate after a few shots and I don’t know why it is the only problem I have ever had with this gun

    • Jardo,

      I think I can help you but I need to know the type of airgun you have.

      And are you using the artillery hold if you have a spring gun?

      You can respond on the current blog. That way close to 60 thousand readers will see your comment and be able to join us.



  22. I have no idea what an artillery hold is to be honest this is the only pellet gun I have ever had that was worth anything it’s a big cat 1250 I use it mainly to but I target shoot too. I have a 5 screw bracket on the dovetail and A nice scope on that

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