Another twist on rifling

by Tom Gaylord, a.k.a. B.B. Pelletier

I thought I’d provide some thoughts on how this blog has helped me become a better shooter. We just finished the Twist-rate test last week, and I wanted to share with you some things from that test that have impacted my shooting.

Swaged bullets
I’ve been using the output of the test to guide my own shooting with both firearms and airguns. I did test the swaged bullets in my muzzleloader already, but I discovered that there’s a lot more to learn. I can’t get the bullets I’ve swaged to group at 50 yards to save my life! I get maybe 1 out of 3 shots to land on paper. I think the problem is that I’m driving them too fast. I’ve been using the same load of black powder that I use for a patched ball, which seems like double the amount needed to get good results. When these bullets are fired in airguns, they’re shot at between 400 and 650 f.p.s., and I’ve been launching them at 1,000 to 1,200 f.p.s. I think I’m blowing them apart!

I plan to load less than half the amount of black powder to see if I can get the velocity down around 650-800 f.p.s. The twist-rate test told me these short bullets don’t need to be spun up as fast as I’m shooting them. At least, I think that’s the case. More later when I actually have something to show you.

The AR-15
A friend talked me into buying some Accurate Arms 2230 powder for my AR-15, but when I tried it with the 69-grain and 77-grain bullets I normally shoot, it was lousy. The burn rate of this new powder is way faster than the Varget and Reloader 15 powders I’ve been using, and both given such good results. I figured the problem was  that I was trying to push a bullet that was too heavy with a powder that was too fast.

BB at bench with AR-15
I still can’t get over how accurate my AR-15 is with the right loads.

Good group with AR-15
Ten shots into 0.54 inches at 100 yards is pretty good for an AR-15.

I loaded some lighter 55-grain bullets with the lowest charge of 2230 the book recommends. But the results were poor, again. Oh, they were twice as tight as before, when I shot the 77-grain bullets; but with 10 shots going into 1.808 inches, they still aren’t worth the trouble. It may be that my 1:8″ twist is just too fast for lightweight bullets, but I still need to experiment some more.

poor group with AR-15
Ten rounds into 1.808 inches at 100 yards is terrible for a rifle that can do so much better.

Ballard
I updated you on the Ballard situation a few weeks ago. I told you that I discovered the Ballard’s rifling has a twist rate of 1:20″, while Winchester rifles of the same caliber (.38/55) have twist rates of 1:18″. Given the slow speeds I shoot, the difference is significant. Bullet molds and cast bullets that are available today are all made for the Winchester, which is far more common than a vintage 1886 Ballard.

Ballard
My vintage Ballard turns out to have a twist rate that’s on the slow side for the bullets that are available.

What this means is that I’ve been trying to shoot with bullets that are too long and heavy for the twist rate of my rifle! It took the results of the twist-rate test to drive this fact home. The solution is not as straightforward as it sounds, however. You might think I could just have a custom mold made for a shorter bullet. That’s possible, but I first need to think some things through. For example, would the rifle do better with a full charge of black powder and the bullets that I already have?

I got very discouraged when I learned that my rifle had a slow twist rate. I even considered selling it and buying a rifle that was more suited to what I want to do — which is shoot 10 shots into less than one inch at 100 yards with non-optical sights. But when I tried to list the rifle for sale, I found I could not let it go!

Ballard group
No matter what I do, I just cannot seem to get the Ballard to group much better than this at 100 yards. Ten went into 2.654 inches.

So it’s back to the beginning with the Ballard. I have to figure out how to make this old beauty shoot in its current form because it is too valuable to modify. And everything I do from this point forward will be driven by the slow twist rate!

The next twist-rate test
We’ve finished the initial twist-rate test, but we aren’t finished with the special barrels. Several of you have asked me to test the 1:12″ barrel with heavy pellets that are longer. I’ve decided to test it at 50 yards with the heaviest, longest pellets I can find. But besides that, I’ll also test the JSB Exact Jumbo RS pellet in the 1:22″ barrel at 50 yards. The RS is 0.002″ longer but nearly a full grain lighter than the Premiers that were used in the first test, so we may see an accuracy improvement over the 2+ inch groups the Premiers gave. Being lighter, the RS will travel a little faster, which means it will also spin faster, and that may help the accuracy. We won’t know until we try it.

This is good
I told you when I started the twist-rate test that we might find specific things to test in the future. These are those things, plus a few more. What a ripple effect this has had on all of my shooting!

52 thoughts on “Another twist on rifling

  1. G’day BB
    I noticed on the bench rest photo that you have your face turned slightly towards the stock and your pupil is towards your nose. Do different face positions on the stock alter POI with a scope to any degree?
    Cheers Bob




        • G’day BB
          So if you got that AR stock to fit you to a tee, do you think you could get smaller groups?
          I have been experimenting with a PFS stock on my shotgun and it is amazing how small adjustments cause different POI. I realise it is not the same as scope as your eyes are the rear sights.
          BTW Ballistol attacked the glue under my stick on front sight raising it about 2mm which I could not notice without glasses. For 4 weeks my scores were down because the gun was shooting low and my mount slightly different on the figure of 8. The benefits of age…
          Cheers Bob


          • Bob,

            There are a couple things yet to o with my AR before I look at anything with the stock. AR stocks are not very ergonomic, anyway, and those telescoping ones are a joke in the ergo department. I bought the A2 stock because of all of them it fits the best.

            B.B.



  2. It’s Friday ! So let me show you how I wasted Thursday ( poor shooting weather).
    If you like Dremel tools, drill bits, countersinks, and pipe reamers then skip this post.

    I thought I would show you guys how I do a crown . I used a scrap piece cut from a barrel that I put on one rifle.

    I squared it off with the lathe and looked at the end. Something wrong. No rifling on one side. Closer inspection in better light and from an angle showed this…..
    http://i189.photobucket.com/albums/z244/twotalon/2013-08-01%20001/DSC_0026_zps369253a3.jpg
    That’s not good. The damage extended about 1/16″ down the bore on one side. Not going to crown it here, even if it is a piece of scrap.

    So I trimmed it back a bit and went through my crowning procedure . (Hope this works a second time. )
    http://s189.photobucket.com/user/twotalon/media/crown5/001_zps90d7f4b8.mp4.html

    O.k. After much messy work and time wasted (took a few beers for this job ) I got it done. Looks a bit better than original…
    http://i189.photobucket.com/albums/z244/twotalon/2013-08-01%20002/DSC_0029_zpse3bd91c8.jpg

    So I hope this works. Won’t know until I have already posted.

    twotalon


    • TT
      That is a very nice crown.
      And whats interesting is that when you cut the barrel back some of the rifling didn’t go all the way around. Did it come that way from the manufacturer?

      And BB. Do you really think the swaged bullets were blowing apart. If so could it be from the type of lead. I don’t know. That’s why I’m asking.


      • GF1…

        That’s how it was . I think that snaggletoothed tools and tool wobble cause some pretty strange bore defects. I have gotten hold of some barrels that might as well been hammer forged with a rat’s tail wood rasp for a rifling mandrel. Some barrels have very noticeable bad spots down their whole length.
        This barrel seems to be good except for the first 3-4 inches of the breech end , which I had cut off.

        twotalon



    • I’ll have to watch it on my computer, tt. The movie doesn’t want to show up on my phone… The pics do though and that is a nice looking result!

      /Dave


    • What…there’s bad shooting weather ;-)
      All week long the forecast for my area for today has been sunny and windless, so I’ve made plans to leave work early and head to the range.
      It’s socked it, there’s been some rain and there’s a steady 10mph wind.
      I’ll go out anyways and just deal with the frustration of shooting 2MOA groups because of the wind ;-)


  3. B.B. Hope you are enjoying you AR. I know you are a fan of the M1 Garand. Yesterday my CMP Garand was delivered to me. Overall very impressed with the condition especially for a gun older than me. Looking forward to getting it out to the range. Bub


  4. And therein lies the fun! Who would have thought that playing computer games would help develop everyday decision making skills and driving a car at the same time? Or that riding a bike would help your balance when walking? Our ability to integrate skills and thought processes from one area and apply them to another continues to amaze me…

    Good report, BB!

    /Dave


  5. B.B.,

    I have been considering purchasing the new Walther LGV. I know you bought the one you reviewed because you liked it so much.

    This vid on Youtube gives me pause, however. Notice the compression tube at the 40 second mark in the vid. Very rough looking finish and tool marks. Does yours look like this?

    http://www.youtube.com/watch?v=2coHt6J0Ioc

    I don’t believe everything I see on the web but I thought I’d ask about yours.

    Thanks,
    Mark N


    • Mark,

      I watched the video. No, that gun is rougher than mine. I did use a magnifying glass on mine — to get the extreme magnification that was shown in the video. Mine is smoother.

      B.B.


      • B.B.,

        Thanks for taking the time.

        For some reason I feel like the finish should be nicer. Maybe they put emphasis on other things like tolerances and material quality at the sacrifice of the finish.

        Still undecided, Thanks again,
        Mark N


        • Mark,

          I understand how you feel. I focus more on function than appearance, so I’m inclined to relax my standards more than others when it comes to these things if the gun works well. But when you call my attention to it, I can see it and I can see the difference between the gun on You Tube and the one I have. I don’t know if I would have picked up on it if you hadn’t called my attention to it, though.

          B.B.


  6. TT
    That’s crazy about the barrel with half of the rifling. I wonder what that does to the pellet when it goes through the barrel and how it affects the flight of the pellet when it leaves the barrel.

    Heck I bet it chops part of the pellet off when it hits that spot. And if I’m thinking right that would maybe be a bent barrel?

    Oh. I guess that is a barrel from a pellet gun. Even if it was a fire arm barrel I bet it wouldn’t be good for a bullet.

    And BB what are you going to try next for the Ballard. A softer powder load?


    • I posted to quick again.
      I read above that you are going to slow it down with the softer load.
      But just seems odd that the bullet would blow apart. Seems to me that the lead is too hard if that is happening.
      Or maybe another problem. Sealed to tight to the barrel and to much powder. I think the load is pushing the bullet over the rifling and tearing up the bullet. No spin just a push of some sort???


    • GF1…

      The pellet is going to get a rough ride through places like that. It would probably seem loose at this point . Some barrels must look about that bad all the way through. If you push a pellet through them, it grinds and bumps all the way from one end to the other. Going to remove some of the pellet in the process.

      I have one barrel that looked like that at the muzzle , but all the way around. Looked like someone tried to screw a wood rasp into it. Cutting off about 3/8″ cleaned that up.

      Another of my lemon barrels was nothing but a constant grind-bump-grind-bump from breech to muzzle. Something like a gravel road with 2X4s laid across it in regular intervals. Pushing wadcutters through it, as the pellet reached the crown, there was powdered lead and fine shavings all around the head of the pellet.

      Another had the feel of a file from one end to the other.

      Still another was smooth from the breech to about half way to the muzzle, then turned rough the rest of the way.

      Aside from pellet damage, can you imagine the wild vibration patterns that must get set up as the pellet rides over this crap ?

      Oh yeah…
      The barrel in question was a blank. Looked straight inside and outside.

      twotalon


      • TT
        Maybe I should start looking at the barrel rifling from now on if I’m having accuracy issues with a gun.

        Seems that the manufacturers would have better quality control though. But I guess that goes along with who is making the barrels.


        • GF1…

          Depends on the situation with accuracy if you need to start really looking at a barrel or not. You certainly should not just jump right in and start recrowning right away. It’s easy to louse it up and maybe even make it worse.
          There are a lot of things to look at when a gun is not shooting too well. There are questions like….
          Pellet quality
          Pellet fit
          Kind of power plant
          Does it use a transfer port in the barrel itself
          Is it choked
          What brand barrel (maybe)
          Bad from the start, or did it take time
          Do anything to the barrel
          Clean it, and how was it done
          Probably a few more things that I can’t think of at the moment.

          Some problems you can do a lot about, and some things you can’t. You always have to try not to make things worse.
          It will cost you money for a barrel that is as close to flawless as possible. I like to check the general condition of a barrel by pushing dry pellets through it. TIGHT fitting pellets….from the breech end. The worse it feels, the more I worry about how it is going to shoot. Sometimes just polishing the bore does a lot to improve accuracy. Some are beyond hope. Sometimes the only thing that is wrong is simply a bad crown, no matter how good it looks. So many gremlins. Some times you can go down the whole list of what to look for and what you can do and still not find the problem….or combination of problems.

          twotalon



      • Let us know if you come up with anything after you look at the targets. If you don’t mind.

        And you talk about the swage bullet for the Ballard. But have you swaged anything for a air gun yet and tryed it?


        • GF1,

          I misunderstood your question before. I thought you were asklng about the Ballard.

          I don’t have any targets to examine for the swaged bullets, yet. But this coming week it is my plan to shoot the rifle at 25 yards with a reduced load of powder and see if I can get something started. If I get any groups from that, I’ll write Part 2 of the swaged bullet test.

          No, I have not shot swaged smallbore pellets yet, but nearly all Air Venturi big bore bullets are swaged and they work quite well.

          The swage is not ultimately for the Ballard. It’s for my Nelson Lewis combination gun.

          B.B.


  7. TT
    I have crowned a few barrels through out time and I know what you mean about easy to mess up a crown.
    And I understand everything you said above. But I wonder how many barrels do leave the factory with bad rifling or crowns.

    I do know that when I order a barrel from Crosman they always say it will be a couple weeks before it ships because they have to crown the barrel.
    Never understood the exact reasoning behind the 2 weeks.

    BB
    I decided to go with my .25 cal. Marauder to try swaging a bullet. I think it has the best power available of the air guns I have.

    The problem I’m having is with myself….I don’t want to take the barrel out of the gun to push a pellet through to get the size for the swage diameter. The gun shoots to good and I don’t want to take it apart.
    So I’m going to cheat and make a couple different diameter tools. I’m thinking .253″, .254” and .255″. Or I can actually start out at the .253” diameter and open it up with a tapered reamer if I need to make the bullet/pellet fit tighter to the bore.

    I think I will wait till you write Part 2 though. Hopefully more good info from that test.
    I’m still not quite ready yet. I need to find something close to the .25 cal. size to swage.


    • GF1

      There are probably quite a few barrels that are “not so hot” that come off the line…..from a lot of different manufacturers. Mass production and the need to keep price down for the larger potion of the market tend to lower the standards. Power and gimmick hype drive the larger portion of the market. That’s where the money is.
      I don’t want to talk about Crosman’s barrels . Been there with them over a 2300T.

      The whole thing makes me want to say “send me the rifle and a dozen extra barrels…I will pick the barrel I want and send the rest back to you” .

      twotalon


      • TT
        I guess I have been lucky with my guns.
        But I did get a new .177 Disco ( messed my old Disco up trying to mod it a long time ago and I missed shooting it ). The new one just doesn’t shoot as good as the old one. Even used the old scope and mounts.

        So I had the old barrel and receiver on a 1377. Took it off and put it on the new Disco with the above scope and mounts. Guess what. It now shoots good. So there must be something going on with the barrel or receiver or both from the new Disco.

        I actually just got finished putting the new Disco barrel and receiver on the 1377 and getting ready to give it a try. And I really couldn’t see anything wrong with it though. So I guess I will see what happens.


        • The new Disco barrel and receiver shoot the same on the 1377. Its not real bad but just not like the old barrel and receiver.
          The new barrel will shoot about 4 or 5 shots good then throw a flyer. That bothers me. If I’m target practicing or plinking I can kind of live with it. But if I’m on pest control I don’t want the flyers.

          I think I’m going to take the barrel and receiver off and take a closer look to see if I see something wrong. I even tryed different pellets with same results. I did use a different scope and mounts this time but still same as above.


          • GF1

            Look at the breech end first.
            Snags there will cause trouble. Then there is the wonderful idea some engineer came up with…..bolt probe too short. It leaves the skirt of the pellet hanging half way over the transfer port.

            twotalon



            • TT
              I did check out the breech of the barrel and the bolt. And I found something interesting.

              I remembered when I was trying the different pellets that a few different brands felt like they were kind of hitting something when I pushed the pellet in with the bolt.

              Guess what. I could see a slight chamfer on one side the rifling and not on the other side were the pellet loaded into the barrel.(maybe a little on one side but definitely not equal all the way around) I put the barrel in the lathe and took about .010″ off the face and gave it about a .015″ chamfer in the rifling after facing it.

              Put it back together. Loads smoother and have shot about 50 rounds total of different pellets and no flyer’s yet.

              I don’t know if you call that crowning a barrel but same principal as crowning the muzzle end.

              All I know is it worked and I’m happy. Thanks TT for pointing that out.


              • GF1

                That’s a common problem area for “bolt action” guns. I have one that was hideous for accuracy at 15′ before I lapped the breech end.
                I like the pellets to load with fairly light and smooth force. “Pressed in” instead of “snapping in” with a lot of force required. It’s a warning sign. Good that you were observant enough to spot and remember this.

                I would polish the breech by hand as an “extra” myself. Cleaning rod, jag, hard weave cotton patch, and polishing compound . Working it in and out just far enough to smooth the area.
                If it does good enough for you, you can leave it alone without going to the extra trouble. It may or may not make any difference.

                twotalon


  8. off topic a bit. I am new to shooting and am learning so much from your blogs and the folks here. I have a springer and love it. However I want to be focused on getting it sighted right. I wanted to try using a gun table and a gun mount. can you give me some heads up on both. I have the basics of sighting down but my accuracy is unsteady just bracing it on a stick. So I wanted to use a more stable and reproducible shot platform. I know that the PCPs would be far more stable a shot but I like the simplicity of springers.



      • Yes I am sorry I mean Rifle rest. see how new i am. I wanted to see if I could set a springer in such a manner that I could rest the rifle in the same location and direction to get a “repeatable” shot pattern to test pellets. I understand the artillery hold technique,but even that technique has to have a repeatable format available somewhere.I guess what I am looking or is a device that I could “rest” the front of the gun on both horizontally and vertically that would give me a reasonably reproducible shot while still allowing the free movement of the artillery hold.Does this make sense? I m just be unable to describe what I want. I guess it would be like a wide-rest with a vertical pole for left /right control with perhaps a level? Or should I just invent it and become rich LOL


        • Nick,

          Yes, a rest would be wonderful, but it just doesn’t work with many springers. Some, like the TX 200 are almost immune to resting, and the FWB 300 works fine when rested, but most of the rest of the springers have to sit on the flesh of your hand.

          The secret to repeatability is to always rest the stock at the same place every time. For me that’s usually with the heel of my hand touching the triggerguard.

          B.B.


        • Presuming a break-barrel, the only firm rest would be some sort of L brackets bolted to a cement bench (I’d think 500lbs might be sufficient mass [yes, I know lbs is a result of gravity and varies by location, whereas mass is an inertial concept and is the same regardless of location]). The L bracket would be needed to ensure the action can be cocked without removing the gun from the clamps.

          But all that will do is reveal the native accuracy of the barrel; using that to set a scope (or open) sight won’t reflect the point of aim from a hand-held (or any other flexible) support.

          You are asking for a rifle equivalent of a Ransom (machine) Rest — but no one uses a Ransom Rest to adjust sights; they are purely for testing the repeatability of the barrel/ammo mix without sighting.


  9. B.B.

    This Saturday I mounted a scope and zeroed it in for my friend’s Anschutz 1416 HB. I couldn’t miss the opportunity to check twist rate and it was somewhat close to 420 mm, 1:16,5. Extremely precise machine, I was able to repeatedly hit empty 12 gauge shells into the base @ 100 m with Lapua ammo.

    duskwight



      • B.B.

        Well, they are shooting experience pushed to the very limit of the word “shooting”. Everything moves, or rather slides with a kissing sound, gentle push of the recoil and another hole in the paper. You can hear dry “puff!” and then when a bullet flies its 100 m @340 m/s and hits the paper on a cardboard – “tok!”. Amazing stuff for an evening at woods range.

        duskwight



        • Yes, that’s why I dropped money for an Anschutz 1907. This way I can experience all the great rifles I hear about. It’s a work of art as much as anything. But I shoot it far too infrequently.

          Matt61


  10. With that opening photo I would say the story of The Seduction of B.B. Pelletier is well-nigh complete. I bet if you could have seen that picture in earlier years, you would have freaked out! Well, one great service of this AR saga is as a corrective to a lot of gun articles. There are some very dubious stories about AR accuracy. For instance, I was reading an article on Cheaper Than Dirt about some wonderful new AR. There are low-grade ARs and mid-level ARs, and then there one’s like this particular one that was being profiled. After the usual raving about its fit and finish and various accessories, the article got down to its “absolutely dead-nuts accuracy.” This was all of 1.5 inches at 100 yards!?

    Obviously, B.B.’s test leaves no doubt that the rifle can shoot. Inquiring minds will want to know why. I had heard some time ago about how the SR25 was the absolute pinnacle of rifle design that took technology to its limits. I dismissed that as hype, but B.B.’s results give one pause. This rifle seems not only to have made up the ground to bolt-action rifles but even surpassed a lot of them. The lack of a piston would remove a source of inaccuracy. The target style stock is all to the good. But all that should give you no more than parity with a bolt gun. It’s kind of a mystery.

    Yesterday, I shot airguns for the first time in over a month. Not since I started seven or eight years ago have I gone so long without shooting. My first shots were horrendous–an inch low at 5 yards. This really is a perishable skill. But I sprang back quickly enough, and while I haven’t gotten it all back, the essentials are there. I need to put in a lot of time airgunning….

    Matt61


  11. b.b. have you ever went to see the J.M. Davis museum?> john collected a lot of ballards . I was in there Saturday for mabe my 15 gazillion time . my dad was a close friend to john and I seen his collection a lot when it was very small[6000 guns] its worth your time. he has about every gun made including a lot of air guns and spring guns too .


  12. B.B.,

    Thrilled to hear that you’re not giving up on the Ballard.

    Can’t help but believe that there is some secret to unlock the accuracy potential in that .38-55 otherwise why would so many Ballards have been used in competition? Is it because many were rebarreled? Don’t think black powder is the sole answer but maybe part of the equation?

    I know you don’t have these answers. Yet. Really appreciate the updates though and hope your analysis of previous targets provides you with some direction.

    kevin


  13. yes b.b. in Claremore. my dad was a close friend with john and I was there a lot when I was 5 and up. every time we went down, I can still hear him tell me ” bob go look over there on that west wall” I got a few new guns. anyway they have a deal with daisy. you order a new daisy and its got a monomagramed stock with j.m. davis signature. I encourage anybody in the area to go visit the museum. its kept up by donations and is the worlds largest private gun collection. I was looking at some very old air guns . 1 had a leather bladder in the stock and was a 37 yes 37 caliber . I think it was similar to the guns lewis & clark carried . sorry it took me some time to get back bb but I was out in Kansas in the floods .strange to see a flood in Kansas and in august at that too



    • ajvenom,

      Writing this report is me giving the devil his due. I have criticized the AR family of guns for more that 40 years, and now I am making amends because I own one that can really shoot.

      B.B.


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