BSA Comet breakbarrel air rifle: Part 2

by B.B. Pelletier

Announcement: JrSquirreler 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.

JrSquirreler shooting his Crosman Nitro Venom Dusk .in 177 caliber using the artillery hold.

Part 1


It’s medium-sized and lightweight. The velocity in .177 is 825 f.p.s. The BSA Comet is a different air rifle.

Today is velocity day, and I must say there have been a lot of comments about this BSA Comet. Many people believe that it’s nothing more than a Gamo in disguise, and they’re prepared to see Gamo performance, which wouldn’t be up to the same standard as BSA in days gone by. The gun was made for BSA rather than by BSA and it looks a lot like a Gamo, so these folks are probably right about who made it. But for the price tag it carries, I expect to see a lot more performance.

Cocking effort
The first thing I did was measure the cocking effort, because as I mentioned in the first report, there was no number given in the specs. I measured the effort on a bathroom scale. If you’re interested in how this is done, watch this Airgun Academy video.

The BSA Comet cocks with 33 lbs. of force. The cocking stroke is rough, as though the inner parts are not well-lubricated or are roughly finished. It felt like a gun that has a lot more power potential than what s advertised.

7.9-grain Crosman Premiers
The first velocity test was with Crosman Premier lites, the 7.9-grain dome that we usually use as a standard test pellet. In this rifle, they averaged 793 f.p.s. with a spread that ran from 787 to 796 f.p.s. There were a couple powerful detonations in the beginning before the rifle settled down to normal. At the average velocity, the rifle generates 11.03 foot-pounds with this pellet.

7-grain RWS Hobbys
Next, I tried the 7-grain RWS Hobby pellet. Before the non-lead pellets were around, this was the standard pellet we used for high velocity in airguns. In the Comet, Hobbys averaged 850 f.p.s. The range went from a low of 840 f.p.s. to a high of 874 f.p.s. I noticed an increase in vibration when Hobbys were shot, so they’re probably not the best pellet for this rifle. They generated an average of 11.23 foot-pounds.

By the time I was finished shooting the Hobbys, my office smelled like a lumberjack kitchen where bacon has been frying for hours. I haven’t smelled that odor for many years, but it put me in mind of all the Chinese spring airguns I’ve tested. They always dieseled a lot and smelled this way, too.

JSB 8.4-grain Exact domes
The last pellet I tried was the JSB 8.4-grain Match Diabolo pellets. Despite the misleading name, these are not match pellets at all, but domes. They’re usually very accurate in most spring-piston airguns, and I’ll be sure to try them in this Comet.

They averaged 766 f.p.s., and the spread went from 758 f.p.s. up to 774 f.p.s. At just 16 f.p.s., that was the tightest spread I saw in this test and it’s indicative of a pellet the powerplant likes. It’s also a sign that the gun is settling down and not detonating as much. The gun vibrated a lot less with this pellet than with the Hobbys. This pellet generates an average 10.95 foot-pounds of energy.

Trigger-pull
And a pull it is. This trigger, which is supposed to be adjustable, really doesn’t adjust so you would notice it. The two-stage pull is one that allows you to remove a part of the stage two pull by pulling part way then relaxing your finger. When you come back on the trigger, the second stage is now where you left it. So, the loooooong creepy second stage can be pulled off progressively, if you like.


The single trigger adjustment screw is buried so deep inside the trigger unit that you have to remove the stock to get at it. I did, but despite gross adjustment, I felt no change in the trigger-pull.


The BSA Comet trigger that I promised to show you. It’s definitely descended from a Gamo trigger, but it appears more modular and modernized than Gamo triggers I’ve seen. The large bar that extends off the the left at the top of this trigger is part of the anti-beartrap device.

It felt much heavier than it is. My RCBS trigger-pull gauge says the sear releases at 3.5 lbs. every time. Of course the fact that the safety is entirely manual and does not come on during cocking is a big plus.

Current observations
I’m now feeling ambivalent about this rifle. I still like the light weight, but the buzzy firing cycle and creepy trigger don’t do justice to an airgun in this price range. It’ll redeem itself if it turns out to be accurate without the need for a lot of technique.

87 thoughts on “BSA Comet breakbarrel air rifle: Part 2

  1. B.B.

    Looks too Gamo and smells too Chinese for me.

    I got my data posted yesterday. Rather than some long explanation as to what it’s telling me, it looks simple enough that a reader could figure out quite a few things by themself.

    twotalon


  2. I dunno, BB… to me that looks EXACTLY like the Gamo triggers I’ve serviced. I”m guessing it’s not Chinese, at least, but I could be wrong…


    • That trigger is exactly like my gamo trigger.
      BB could remove the spring in the trigger peace so it could be much light.
      And as my gamo trigger, the adjustment screw does nothing (my screw is too short).

      Please BB remove the spring of the trigger peace and test it again if you feel any progress.
      This rifle also looks to be limited to the UK limit of 12 foot-pounds…




        • BB,

          Count me in with the others who say the trigger looks like a gamo. I have had and worked on several gamo’s. Looks exactly like em to me and the gun does indeed have all the tell tale signs of a gamo heritage.

          I would bet Charlie Da Tuna’s triggers would work in this to solve the trigger pull quandry.



  3. No – this has the solid steel barrel and open sights (which the Big Cat does not). I also believe that Gamo cheapified the trigger on the more run-of-the-mill guns. So I suspect it’s more of a rebadged and restocked Gamo Shadow of about 6 years ago – which could be had for about $125 at Walmart.


  4. Poor trigger………stirke one…………..expensive for what you get………….strike two…………

    It doesn’t look good so far.

    Happy Friday!

    Mike


  5. This one is starting to look like a dog. Not smooth to cock, buzzy when fired, these attributes might be forgiven on a magnum powered gun, but not one of this power level. Add to that a junk trigger…

    When compared to the Polaris, which is only $35 more, the Comet seems to be a lost cause.


  6. Too Bad. Missed opportunity seems to be the consensus. Even if it is accurate, for only another $50 you get a rifle that has and excellent trigger and build quality. Doesn’t make sense. I have to ask myself – what were they thinking? Kind of like the airgun classifieds. It seems like everything for sale was tuned by Rob Hawkins and/or that the seller deserves to make a profit.

    On another note, I saw the Browning Gold air rifle on the PA website last night. I personally think the stock looks like a Pontiac Aztec, not exactly my style, but I had to give them kudos for trying. In looking at the pictures it looks like there is a barrel latch and I couldn’t figure out where it is sourced from. It doesn’t look like any of the Chinese models on the market. Does anyone have any idea? Could this be an interesting test rifle for you B.B.?



      • Do you mean you’re awaiting Mac to arrive right now? If so, I have to comment on the timing. First I asked about the Talon and you were working on your “What Would BB Do” and now I’m asking about the Browning when you’re waiting for Mac. There must be some sort of Psychic conduit between your blog schedule and my airgun interest, or maybe I just spend too much time thinking about airguns in general…Nah, that can’t possibly be it.



          • As a matter of fact, I have a neighbor who’s preferred method of squirrel control is a rimfire .22. He says they’re not too much louder than a pellet rifle. And, well that got me thinking…


            • Sigh. I’m SO busy right now, I haven’t messed with my primer powered pellets that I got a Ruger Single-Six specifically to experiment with. (Ideally I get decent velocity with a .22 pellet with a very quiet report, and 6 shots with consistent velocity and no pumping etc in between.)

              BUT …. I was being weird one day and shooting primer powered stuff out of my Marlin bolt, and I seem to remember taking a CB Long and cutting off the bullet at the case rim, leaving a little “nub” of lead in there, and shooting that, and it was quiet! The lighter weight of the “nub” resulted in less pressure and so, less noise?

              Use a Stanley knife or a pair of GOOD electronics-type diagonal cutters and you can “snip” .22 bullets pretty neatly.




      • Kevin

        I haven’t quite worked that out yet. I don’t have any high end match pellets, only RWS hobbys (which don’t group well) and Crosman wadcutters. What pellets do you recommend?


        • Slinging Lead,

          Re: Pellets to try in the HW55S

          With the assumption that your gun has the export spring or equivalent and is shooting to spec and based on your 6 digit serial number in your photos that indicates an early gun that MAY have a flared-breech I’d recommend trying:

          For short range/10 meter paper punching

          Meisterkugln heavy and light pellets
          R10 Match 8.2 gr

          For longer range the following domed pellets

          Air Arms Field (especially if it has a large breech)
          Superdomes (especially if it has a large breech)
          Air Arms Falcon
          jsb exacts
          jsb exact express

          kevin


        • Slinging lead,

          Good looking.
          Makes my $130.00 HW50 look like a a fence post.
          I would guess about 520 – 545 fps with average 7.9 gr pellets.

          Marauder came yesterday, should keep me occupied for awhile.



            • On the Marauder?
              I have a full size Centerpoint swat that has the 30 mm tube and side focus on the bench that should match well. Just need two piece mounts, unless I find some hidden.

              Biggest surprise so far is that the M-rod weighs in at 8.5 lbs sans scope, mount, and magazine. Wow!
              Box says 7.1 lbs? Other than that it looks pretty nice, fit and finish are all acceptable. Barrel band is mis-aligned , but an easy fix.


              • I have the same scope on my .22 Marauder. It’s a good combination. Since it was such a big fat pig with that huge scope anyway, I went ahead and added a bipod.



      • BB

        The trigger is a dream. It is probably adjusted a little heavy for a target trigger, but it is so predictable you almost don’t notice how great it is when you don’t have to think about it. The fact that it is an older rifle, with well worn trigger parts doesn’t hurt either. Do you have any pellet recommendations?

        I will post some velocity info as soon as I get it.


        • SL,

          I don’t really have any pellet recommendations, since my 55 SF shoots Hobbys best of all, and your rifle doesn’t like them.

          I will be testing the 55 CM soon and I expect to have some different pellets then, but you will have already found some good ones by then.

          If it was my problem, I’d look at RWS R-10 in both rifle and pistol weights, with the largest head sizes you can buy.

          B.B.



      • Those hinges are marvelous and, oh, that rifle isn’t bad looking, either. A great find, SL. Congratulations.

        Fred PRoNJ



    • SL,

      Congrats on a nice springer… that’s one even I would enjoy shooting. That is just the right power level for a spring gun. And the build quality is top of the line. I’m sure you’ll enjoy it for a long, long time. I’ve got an extra sleeve of “Cometa” version of the JSB 7.9gr Express… I could send you a couple tins to try if you would like. They shoot well in my 12fpe rigs.. might do well in your new HW-50

      Wacky Wayne



  7. I was pretty surprised when I saw the price of this gun in Part 1. Now after Part 2, it’s not getting any better. There are a lot of very nice guns in this price range. The accuracy will have to be pretty special to make this one worth it.
    Lloyd


  8. Hooray to JrSquirreler for being this weeks Pyramyd Air winner.

    I really like to see a young man that is quickly developing his shooting skills. Thanks. You made my day.

    kevin


  9. I have to agree that a bad trigger and a buzz are pretty bad, individually unacceptable and together….

    Congratulations to JrSquirreler. He looks like he has the artillery hold down well although I would recommend a more bladed stance. However, I haven’t seen his groups.

    Great job Wayne–a world class field target shot. Now, I see why you kick butt in the business world.

    Okay, for the rifling angle for a twist rate of 1:9 in a .223 barrel, it looks like the answer is .7098 degrees which is slight indeed. Again that is the angle between the rifling and the bore axis. This comes from an independent source who ran my numbers independently. It looks like I messed up in the calculation which is not a surprise. I have some quibbles about just how this was done, but I’m sure the answer is in the ballpark. Anyway, that quantifies the lovely geometry you see when looking down a rifle bore which I find quite mesmerizing.

    Matt61


    • That number sounds rather small, but maybe I’m not visualizing the same measurement you are…

      1:9, as I recall, means one complete turn in a nine-inch length…

      Diameter is 0.223 inch, circumference is 0.223*Pi. Split and unroll gives a rectangle of

      0.223*Pi x 9 => 0.7006 x 9, wherein the long edge is parallel to the axis of the bore

      One turn would be the diagonal: sqrt(0.7006^2 + 9^2) => 9.0272, giving us a right triangle of

      0.7006 (a) x 9 (b) x 9.0272 (c)

      Now to find my trig books to figure out which pair of numbers gives the sin vs cos vs tan…

      tan(theta) = a / b
      tan(theta) = 0.7006 / 9
      tan(theta) = 7.784E-2
      theta = arctan(7.784E-2)
      theta = 4.4512 degrees

      sin(theta) = a / c
      sin(theta) = 0.7006 / 9.0272
      sin(theta) = 7.761E-2
      theta = arcsin(7.761E-2)
      theta = 4.4512 degrees


      • {o/~ … Talking to myself in public … o/~}

        Or did I over simplify… I was about to take the basic formula for a helix from a calculus text book, modify it to account for “non-unit” measurements (that is, radius not equal to “1″, and similar for length), then integrating it down and computing the angles between two points on the helix…

        Ugh… I barely passed that section of calculus in the first place…


      • Addendum: Using same formula for .177 and .50 caliber, and retaining the 1:9 inch rate

        theta = arctan (Pi*caliber / lenth)

        0.177 => 3.536 deg
        0.500 => 9.900 deg


      • Ha, I love this. I had thought of the toilet paper roll as merely a useful image, not as a method of calculation. I am not quite clear in my mind whether the rifling helix really would be the diagonal of the rectangle as you describe it, but it seems compelling. Supposing this is true, I don’t believe you need to do any calculus. I’ll have to think about this.

        Matt61


        • Well, consider laying a rod, parallel to the long edge of the sheet… consider the point at which the diagonal line crosses (under) the rod… That instantaneous angle doesn’t change even if you unflatten the sheet (wrapping the rod).

          I suspect the software will lose the formatting (Python uses indentation to control blocks):

          from math import *

          CALIBER = .223 #inches, diameter
          TWIST = 9 #1 turn in TWIST inches

          def helix(deg, diameter = CALIBER, rate = TWIST):
          radius = diameter / 2.0
          radian = radians(deg)
          x = radius * cos(radian)
          y = radius * sin(radian)
          z = rate * (deg / 365.0)
          return (x, y, z)

          print "\n"
          for i in xrange(1,11):
          d = 100.0 / (10.0 ** i)
          print "Rotation = %s" % (2*d),
          h0 = helix(-d)
          h1 = helix(+d)
          deltah = (h1[0] - h0[0],
          h1[1] - h0[1],
          h1[2] - h0[2])
          print "\tdX = %s\tdY = %s\tdZ = %s" % deltah,
          print "\tAngle = %s" % degrees(atan2(deltah[1], deltah[2]))

          This snippet is using the equation for a helix to obtain x, y, z coordinates given an input angle (rotation around the bore), taking into account caliber and twist rate. To minimize error, I calculate the coordinates for equal angles to either side of 0.0 (which is why the dX is always 0.0 in the results to be shown). I then obtain the arc-tangent for the difference in coordinates Y and Z. The loop is iteratively using finer and finer rotation angles — in essence, I’m approximating the limit as the rotation approaches 0 degrees.

          Results:

          Rotation = 20.0 dX = 0.0 dY = 0.0387235436197 dZ = 0.493150684932 Angle = 4.48980900585
          Rotation = 2.0 dX = 0.0 dY = 0.00389188663551 dZ = 0.0493150684932 Angle = 4.51236244534
          Rotation = 0.2 dX = 0.0 dY = 0.000389208225595 dZ = 0.00493150684932 Angle = 4.51258831641
          Rotation = 0.02 dX = 0.0 dY = 3.89208421219e-005 dZ = 0.000493150684932 Angle = 4.51259057515
          Rotation = 0.002 dX = 0.0 dY = 3.89208423175e-006 dZ = 4.93150684932e-005 Angle = 4.51259059774
          Rotation = 0.0002 dX = 0.0 dY = 3.89208423195e-007 dZ = 4.93150684932e-006 Angle = 4.51259059797
          Rotation = 2e-005 dX = 0.0 dY = 3.89208423195e-008 dZ = 4.93150684932e-007 Angle = 4.51259059797
          Rotation = 2e-006 dX = 0.0 dY = 3.89208423195e-009 dZ = 4.93150684932e-008 Angle = 4.51259059797
          Rotation = 2e-007 dX = 0.0 dY = 3.89208423195e-010 dZ = 4.93150684932e-009 Angle = 4.51259059797
          Rotation = 2e-008 dX = 0.0 dY = 3.89208423195e-011 dZ = 4.93150684932e-010 Angle = 4.51259059797


          • Yep, lost the formatting…

            Indent everything between “def” and “print”, also indent everything between “for” and the end (do not indent the line with “def”, “print”, or “for”. Then also indent the two “h1[…” lines to line up under the “(h1[…”



      • By Jove, I think you’re right. I get 4.4 degrees with this method which seems completely sound and much easier. I’ll have to consult.

        Matt61


      • I think that the equations that I provided are fairly straight forward, and should work. My only question is, would this helix map into a straight line, if you “un-rolled” the barrel, as Matt described with the toilet paper roll. I’ll have to see how close the results will be to what you show here. I’ve just been too busy and in pain, to do the calculations. The algebra and calculus is the easy part for me. I don’t like to do tedious numeric calculations. Don’t know why, but that’s always been the case with me. In the past, I’d normally just write a piece of code, or use Math-Cad for this kind of stuff. I haven’t done this kind of stuff in almost 15 years.

        There is one issue that I see here. The helix is computed using the RADIUS, and not the diameter. So you’ll need to adjust your calculations by half the diameter.

        Victor


        • Ok, I see. You’re not using the radius because you’re gone straight into computing areas, instead of applying the radius to the helix vector function, (cos(t), sin(t), t).


          • Circumferance, not area… And in the helix function in the Python source I do divide the caliber by 2 to get a radius.


    • Matt61,
      I’m a bit rusty at this sort of thing, but the completion of my derivations, reducing things to algebra, do work.

      I was able to arrive at the same solution 3 ways:

      1. Continuing as I started a couple days ago.
      2. Applying the simplification described below, and computing the inverse cosine between two conveniently chosen vectors.
      3. Taking the simplest path, by converting the slope to an angle using the arc tangent.

      In any case, here’s the simplification that resulted in a nice closed form solution. At some point in my derivations a couple days ago, I computed the tangent line to be,
      L(t) = t (0,R,1) + (r,0,0),
      (this time factoring in all constants, and applying the chain rule).
      I then realized that the slope of this curve is just the derivative, giving me the following,
      L’(t) = (0,R,1).
      We can now have a choice as to how we go about calculating the angle. The scalar equation based on inner products and norms will work, but looking at the physical geometry, and the fact that the slope is just L’(t), our problem reduces to two equations:

      1. R = 2rPi/T, where r is the radius of the bore, and T is the period.
      In this case, r = 0.223′/2 = 0.1115′, and T = 9′

      2. A = arc-tan(R) (* 180/Pi – for degrees)

      I get that the angle A = 4.4510244083411729388745137726254 (your mileage may vary).

      Victor


      • So in the end, Wulfraed and I arrived at equivalent simplest solution. Whereas Wulfraed used ingenuity with algebraic formulas, I relied on straight derivation using vector calculus. Very cool! :) Now, either we’re wrong, or your resource is wrong. Wulfraed and I compute, effectively, the same values, while you’re value is VERY different. Are you sure it’s not 0.07098 radians? In that case, it would be 4.06685 degrees, which is closer to what Wulfraed and I got. If not, then one of the solutions is WAY OFF. Either way, the computed numbers don’t agree.

        I guess one way to prove this is to take a sheet of paper and a tube of some radius and length, compute the angle, and see if drawing a line at the computed angle will cause the line to wrap exactly one period.

        Victor


      • Ok, if C is the caliber (e.g., .223), and r = C/2.
        Then C = 2r. Therefore, R = 2rPi / T. Or R = C Pi / T.
        Then the final equation is just,
        ———————————————————-
        A = arc-tan(C * Pi / T) (* 180/Pi – for degrees)
        ———————————————————-
        i.e., A = arc-tan(0.223 * Pi / 9)

        This just eliminates one extra multiply from my original solution. No biggie, unless you had to do this calculation LOTS of times, which we don’t. Whoo-hoo!



    • Thanks Matt, and all for your kind comments..

      Here is my full report on the Journey:

      My Journey to the Air Gun Bench Rest World Championships in S. Carolina
      By Wayne Burns

      It all started in early Jan. 2011, when Larry Durham convinced me to try out for the USA bench rest air gun team, LD doesn’t like flying, like myself, and figured if he could coach this rookie into a qualifying score, he’d get a ride to the world match that would most likely never be in America again in his lifetime. I had traded with Tim for USFT #27 with a stainless steel Bench Mark .22 cal barrel… Tim and LD were trying to make a statement to the world about the accuracy of the USFT in the bench rest game. They had already made that statement in the field target game with many victories for the USFT. LD had tuned #27 to 30fpe with JSB 18gr. The first time I shot the gun, was a fun match the day I picked it up at LD’s place. We were shooting 10 – three shot groups at 50 yards. I won that contest with the total average center to center of all 30 shots being .343.. HMMM.. maybe LD is right, I CAN play the BR game with this rig..

      But, the game at the world championships was 12fpe and 20fpe at 25 meters… not 30fpe at 50 yards… so, should I tune down this great shooter to 20fpe? Or, change USFT #6, (the gun that won the 2005 national FT championship), into a bench rest rig. I decided to do both. But now, I had to test them both in different wind conditions, to see which one to shoot to try and qualify, and if I did qualify, to shoot at the world championships. That was for a 20fpe rig.. what about the 12fpe part of the championships? So, I made a deal with Tim for a couple 12fpe USFTs, one for me, and one for Tim to use and lend out to other shooters. LD tuned them, and they both shot less than ½”- 5 shot groups in LDs tunnel. Time to practice!

      Ron Silveira from the “Wild River” BR club in Grants Pass, Or, noticed my postings on the yellow forum, and invited me to shoot at their bench rest matches. This was a great help, that club has tons of experience, and Ron especially, shared it very freely! I was so blessed to get professional advice, and a great deal on a quality front rest from Oliver, one of their members. These guys can really read the wind and shoot great. They would have done very well at the worlds, but chose not to make the journey… (Too hot, too buggy, too long away from home, costs too much money.. too, too, too.. blaugh, blaugh.. any one of them could have won the event, but especially Ron).
      I soon found out that quality flags were very important.. and learning to read them even more important! This is a part of the game that really takes a lot of experience in different conditions. Only time at different ranges can give that to you… most ranges have tall side berms that create up and down drafts. As the sun warms the ground, your pellets rise. Minor temp or wind changes can move your pellet ½” in the opposite direction you’re thinking… right after you plugged 3 Xs in a row on the seemingly same flag condition. (costing 5 points and the match in one misjudgment) The lucky contestant gets 25 times to guess the wind conditions… 25 make or break shots. There is a luck of the draw for being in the first relay (normally the wind is calmest early in the day), and bench assignment, you move 6 benches up with each relay, assuring each shooter gets a taste of the different conditions on the range.. One can go to their sight in bulls at any time for test shots. You cannot get up from the bench or refill your gun until the match is over. The next two relays shoot… Then your relay shoots another card.. etc.. for a total possible score of 750 – 75X. An “X” is totally removing the center part of the bull… and this count is used for tie breakers. Any way back to the journey…

      I set up a range and got registered as a Bench Rest club, and we started having matches here in Ashland too. The coaching I got from Ron and Larry was enough to get me qualified for the “B” team in both LV and HV classes. The range here in Ashland has some tricky winds like LD’s range in Temecula, just not as extreme. It looks like the tough training conditions LD had to deal with at his place, helped him a lot. The Grants Pass range also has the seemingly unpredictable up and down drafts, but not as violently… or as often.

      The trick I’m seeing that works for the top shooters, is to find a condition that SHOULD occur enough times over a match… (one can only really do this by shooting at that range for a long period of time)… set your zero on that condition, and WAIT for it!!!! Guessing how much hold over for that minor change you see in that best condition, is a bad habit that costs points, and one I’m still trying to break…

      Of course, sometimes your bench assignment puts you in a lane that is switching conditions every few seconds… as was the case at the Worlds for most shooters. The shooters that either lucked out, and got the lanes with more steady winds all three relays, and/or more accurately adjusted with better flags and flag reading, rose to the top.., the latter, for some shooters, the former in my case, since my only decent card, a 245/250 in the 20fpe HV class, was when I had a bench that my flags showed some long periods when I could hold on the 8 ring and get blown onto the 10 ring with regularity.

      The dreaded lanes were the ones on the edge of the air curl or wave that reflects off the forest wall. Depending on the velocity of the gusts, the curl “tubes” out and leaves a dead spot on the edge. Flag tails seem to lay calm, but they are twitching and most of your line of flags, are saying different directions… Flags in lanes to your right are steady left to right, flags three lanes to your left are steady away… you think, “I’ll take a sighter shot and see what happens”.. a nice “X”! OK, go for it dude! … quickly, you dial back to a counting bull and the same hold jumps ¼” high for an 8! Am I sure I like this game??? I drive 3,500 miles each way for this punishment!.. OK, onto the next agonizing bull… and so it goes… until a row of 5 – tens & “X”s keep up the spirits… but for this rookie, they came not often enough to rise more than half way to the top of the list of world shooters present. Personally, I’m fine with my rookie mistakes, but I let down my fellow LV “B” team members, and for that I’m sorry… some other shooters, like Dan Brown on the alternate LV list, (Dan ended up shooting the top LV score, and a record 250 LV card, and he wasn’t even on any USA LV team!)… and LD on the USA alternate HV list, and others ended up shooting better scores than me… but overall team USA really kicked butt… and my team members were so nice about my rookie mistakes, that I can’t feel that bad. My one good HV card, and decent scores on the second two cards, helped earn our Heavy Varmint “B” team, third place and me a bronze metal despite my average shooting.

      But then I add in the many other assets collected on the journey… and my mediocre shooting starts to pale… top of the list, is the many stories Larry shared, and all the world problems we solved on the very pleasant drive along I-40 to South Carolina, in my 1998 V-70 AWD Volvo wagon. The air cond worked so well, even low got us too cold inside the car, while the outside temp gauge said as high as 123 degrees in the S. Ca. desert on our way home. We saw temps almost that high each day on the journey, but the humidity seen from Tenn., east makes 95 more uncomfortable than the 123 in the dry of S. Cal., or 6,000 ft. plains of northern New Mexico. Second, are the many shooters from around the world I met and shared stories, many of whom we plan to continue an email relationship and forum comments, now with a face behind the name! I feel I also added value to my USFT collection by getting four of them used in the completion, and one of them placing third in HV, with Tim shooting it! Here is a link to the final scores and a couple pics… http://benchrest.com/showthread.php?75905-Results-from-Worlds-Airgun-Taken-from-Doug-s-Post-on-Rimfire

      Don’t tell anyone, but journeys like this remind me that S. Oregon is paradise…. My wife and I have been here darn near 40 years since or move from S. Calif., and none of my journeys away gives me a desire to live elsewhere… as I look outside to the temp gauge, I see a very pleasant 79 degrees, under partly cloudy skies, with a cool breeze coming down from Mt. Ashland, full rivers and lakes, green plants and trees, and mostly clean air every day…. Not every where is so blessed.

      Wacky Wayne,
      Team USA



      • Great story and congratulations! Shooting for Team USA, competing with the best in the World, and yet your infernal modesty persists! ;-)

        You and LD riding cross country, that’s one hell of a road trip. It must have been a great experience. Except for the steam bath summer here in the south. This year has been particularly brutal.

        I really would like to try those pellets if I might. I have your email address, I will drop you a line.

        You did us proud Wacky Wayne!


        • SL,

          Yes, send me an email with your shipping address, and I’ll send you some of those Cometa 7.9 to try out in your new rig.

          Sorry that post came out so long like that… I had lots more paragraphs and spaces, but when I pasted it in from word, they disappeared I guess. Maybe Edith can go in and insert some space.. I should have put some titles for the paragraphs too maybe.

          Sorry about that.
          Wayne


    • Matt61,
      What do you know! The very first solution that I gave on August 2nd, was the quickest solution, as it turns out. It would have led straight to the vector, (0, R, 1), at the initial point, 0, which would have in turn given you the exact solution, as my “simplest” solution above (and Wulfraed’s). That was literally a one step solution, starting with the initial equation for the helix, (cos(Rt), sin(Rt), t)’ = (-Rsin(t), Rcos(Rt), 1). At zero, it’s just (0, R, 1). From this, it’s just the final solution above,

      …, if C is the caliber (e.g., .223), and r = C/2.
      Then C = 2r. Therefore, R = 2rPi / T. Or R = C Pi / T.
      Then the final equation is just,
      ———————————————————-
      A = arc-tan(C * Pi / T) (* 180/Pi – for degrees)
      ———————————————————-
      i.e., A = arc-tan(0.223 * Pi / 9)

      Victor


    • Matt61,
      Thanks for the problem! As I mentioned before, I haven’t had to do anything like this for 15 years. I think I learned the basic Vector Analysis for this 30 years ago!
      Victor


  10. Talking of triggers, how to take out the trigger blade from a TX200 MKIII? its a 2011 model and i want to do some mod on it.

    Thanks



      • If its from you, then no offense taken cause i know that you know what you are talking about.
        But if you remember i am from India and that too in a comparatively interior area.

        In figuring out how to take it out i may cause some irreversible damage which can’t be repaired or rectified here, thats why i was taking precaution.

        Why make a mistake when i can learn from other’s ?

        Thanks for the link but its showing a error:
        Forbidden
        You don’t have permission to access /agforum/viewtopic.php on this server.


      • If its from you, then no offense taken cause i know that you know what you are talking about.
        But if you remember i am from India and that too in a comparatively interior area.

        In figuring out how to take it out i may cause some irreversible damage which can’t be repaired or rectified here, thats why i was taking precaution.

        Why make a mistake when i can learn from other’s ?

        Thanks for the link


  11. Anonymous, when you get through Joyce’s Ulysses, you might try Finnegan’s Wake which is even more unreadable. He even published a key which is sort of like another book by itself to help people understand it. Joyce also joked somewhere that there’s enough in Ulysses to keep critics arguing for 500 years, so I’m suspicious that a lot of it is mumbo jumbo.

    However, all of us might be on the same page with Joyce regarding Proust and Remembrance of Things Past. Joyce said that you get to the end of Proust’s sentences before he does. That sounds like your description of this book which I’ve never had a desire to read. On the other hand, in one documentary I saw about Proust some famous associate of his is quoted as saying that in the defiance of convention and mores, Proust “went as far in that direction as one could go.” Sounds like Strauss-Kahn would be a choirboy by comparison. I wonder if that stuff gets into his book.

    Matt61


  12. That trigger, anti-beartrap arrangement and recoil lug/bolt on that action also looks very similar to the Crosman Nitro arrangement.

    Fred PRoNJ


    • It would. The Crosman Quest variants were based off the B18/19, which in turn were based on the older Gamo. There are some dimensional differences, but to the naked eye they do look just about identical.


  13. I have a few off topic questions:

    1. When shooting a Diana 34, should I expect the point of aim to change when I change from off-hand, to kneeling, to prone – because a break-barrel is hold sensitive and my front hand contacts the stock in a different place ?

    2. I need to adjust the rear sight all the way to the left on this particular Diana 34. Does this indicate a mis-aligned barrel – or is it possibly some problem with my cheek position ? If so, what ?

    3. The trigger on this Diana 34 feels like stage 1 is just taking up the slack in the trigger until a spring is compressed, and then stage 2 releases the sear. If I pay attention, I can tell when the spring is fully compressed, and know that the rifle will fire in the next 1/8″. Is this what a 2 stage trigger is supposed to feel like – or is there supposed to be a click or gap in the pull effort to indicate the transition between stages, or something else ?

    4. How does the Daisy 853 compare to the Diana 34 for 10-25m target shooting ? Is the 853 quality level similar to the Diana 34 ? Is there something more accurate than either one (and in a similar price range) that doesn’t require a pump ?

    Thanks,
    John


    • John,

      this is a welcome off-topic – I was getting cross-eyed with the calculations going on in trying to determine angles of rifling in a barrel :) . I would hazard the guess that just due to manufacturing tolerances, you will get a barrel that points left or right or up or down. It could be from the way the action mounts in the stock, the breech fitting into the action or a combination. It could be something as simple as a bent post at the muzzle. That’s why we have adjustable rear sights. Your question on shooting to a different poi based on a different shooting position is something I never thought about. Why don’t you try and come back to the blog and tell us what you found?

      Regarding the two stage trigger, YES, that’s what I like and my triggers do, at least those that are true two stage triggers. The first stage “takes up the play” so to speak until you reach a firm resistance. At that point you know any further pressure and the sear should release – as BB says – like a glass rod breaking.

      Fred PRoNJ


    • John,
      Try applying a small piece of masking tape to the stock at the point where you normally place your off hand. Choose one finger with which to make contact with the tape and use that same finger each and every time you hold the rifle to shoot. With practice, that finger should touch the tape every time without having to stretch to make contact. You can then relax your fingers to execute B.B’s artillery hold knowing that your off hand is supporting the rifle at the same point each and every time. It has helped my off hand shooting. Let us know if it helps yours.
      Pete


  14. 1) John, if you are changing hold then yes, your POI (point of impact) can change. But you can learn to be consistent with your hold even if you change position.

    2) If you have the front sight all the way to the left then something’s not quite right. This should have little to do with your cheek position – when the front and rear sights are aligned they form a fixed line of sight regardless of cheek position. Your barrel might be bent to the right. If you pop the action out of the stock you should be able to tell (by lying it on a flat surface) if the barrel is straight in reference to the spring tube.

    3) Sounds about right.

    4) I think you’d find the 853 is better for moderate range shooting. That’s what it’s made for, with its low velocity and LW barrel. Plus, being a SSP it’s going to be easier to shoot consistently.


  15. 1. When shooting a Diana 34, should I expect the point of aim to change when I change from off-hand, to kneeling, to prone – because a break-barrel is hold sensitive and my front hand contacts the stock in a different place ?

    Does you arm really shift position that much that your hand is not under the same point in all positions? At least to my mind (I’m not a competitor) kneeling and off-hand should both permit the hand to rest on the same spot under the barrel. (My biggest problem is that I tend to position my left hand too far toward the muzzle, and lose support strength)

    2. I need to adjust the rear sight all the way to the left on this particular Diana 34. Does this indicate a mis-aligned barrel – or is it possibly some problem with my cheek position ? If so, what ?

    Since the rear sight (based on photos) is mounted to the barrel and not the receiver, it should move with any movement of the barrel. If you need to move it all the way to one side, I’d be concerned that you might have a bent barrel… Or your front sight is somehow twisted to one side off of vertical. Head position wouldn’t apply except in that a poor position would prevent you from sighting along the line composed of bull-front_post-rear_notch.

    3. The trigger on this Diana 34 feels like stage 1 is just taking up the slack in the trigger until a spring is compressed, and then stage 2 releases the sear. If I pay attention, I can tell when the spring is fully compressed, and know that the rifle will fire in the next 1/8″. Is this what a 2 stage trigger is supposed to feel like – or is there supposed to be a click or gap in the pull effort to indicate the transition between stages, or something else ?

    What trigger group is marked on the receiver?

    The trigger on my old (T01 group, bought from Cabela’s I believe, over a decade ago) mod 54 had apparently been set up by personal injury lawyers — there was no first stage, the entire pull had been a LOOOONNNNGGG and CrReEeEpPy second stage. I’m afraid I had four or five dry fires when I finally started adjusting it a few months ago (after doing a 1st stage mod to add more relief for the 1st stage screw to go in — only to find it wasn’t needed; the second stage screw was bottomed out and needed some four or five full turns out for me to find 2nd stage). I still need to finish that adjustment, on a bench with a pellet trap, but it feels much better already… A nice light (<1lb I'm sure) first stage — which I left long, I could shorten it by turning the 1st stage screw in a few turns since I'd modded the plastic trigger — then a sudden stack to ~4lbs, almost no noticeable motion before it releases. There's no concern with overtravel on mod 54, since the action, with trigger, slides back about a thumb width.

    T05 triggers, I believe, only have the 2nd stage screw. The transition between 1st and 2nd stage should be a sudden increase in the pull weight. 1st stage is a high leverage (long stroke unless you have a 1st stage screw and can preload the stage — that is, you've moved the screw in so far that just cocking the unit has already taken out much of the first stage travel). Ideally (to me), 1st stage should take out most of the sear travel, leaving the sear almost on the edge of releasing, at which point the 2nd stage contact (the screw in adjustables) touches the linkage. This is a low leverage/short stroke position, and is why you should feel the pull weight "stacking"…

    {Then on to Gamo NRA 1000 Special, with GRT-III replacement trigger — it is still rather creepy too, and no felt transition}

    4. How does the Daisy 853 compare to the Diana 34 for 10-25m target shooting ? Is the 853 quality level similar to the Diana 34 ? Is there something more accurate than either one (and in a similar price range) that doesn’t require a pump ?

    For 10m, it’s probably an good entry point… Don’t know if it has the power for longer range accuracy. I have it’s bastard cousin… An early 80s “US Shooting Team” benefit 953 — a 953 receiver and cheaper barrel with the BB loading gate blocked (at the time, the 953 was dual fuel — BB repeater or single shot pellet), but with an 853 wood stock, shooting sling, simple globe front and receiver peep rear (as found on the 853, but without the buttplate shims for adjust length).

    Only a single stage trigger on my 953, and rather high pull-weight — but at short ranges I group better with the peep than I do with a scope.

    I need to retest, but my chronograph test — one sample — had 8.3gr RWS Meisterkugeln (Rifle) doing a mere 450fps… Needs a few cycles and maybe a drop of oil on the pump. The newer Baikal IZH MP46M pistol achieved 438fps with the same pellet.

    The Daisy x53 are single-stroke pneumatics — they don’t pump air into a reservoir (as the multi-pumps do), the reservoir IS the pump chamber; an over-center linkage is used to keep the pressure from blowing the cocking lever back forward.


  16. BB – A good friend has a copy of the 1989 Airgun Review #2, and is looking for the second and third part of the Zimmerstutzen article that started in that issue. Can you or anyone else point us in the right direction?

    Thanks! Jay


  17. B.B.,

    Matt61′s question about finding the angle of the barrel twists really got me wondering about how barrels are actually made and especially so precisely. I don’t have a clue, but I have heard that there are several ways of creating a rifled barrel (at least throughout history).

    BTW, sorry for the messy math. I tried to avoid doing actual calculations, and just provide a lead. Shooting, however, is very mathematically founded, whether talking about barrel twists, trajectories, or sighting in a scope or iron sights. This is part of why Lones Wigger believes that top shots must be intelligent. Just his opinion, but one that I agree with.

    Anyways, would you please do a blog on how rifled barrels are made, both fire-arm and air-gun (assuming they are different)? I think that this would be an extremely fascinating and insightful topic.

    Thanks,
    Victor


  18. BB,
    Ijust read your “Can you keep a clean barrel with Crosman Premier pellets?” and you said, “Maybe someday soon I’ll do a posting on all the snake oil salesmen who haunt the airgunning market!” Did you ever write that one on snake oil?


    • Chuck,

      No, I haven’t written the snake oil report yet. I will think about it and see if I can come up with something that makes real sense.

      The one problem I have is that I don’t want to name any names, but then the article gets so watered-down if I just make vague references. And the wrong people get tarred with the same brush as I meant only for the few.

      I’ll have to think about it.

      B.B.



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