To crimp or not to crimp the 30-30

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  • To crimp or not to crimp the 30-30

    I understand why you crimp a 30-30 round when using tubular magazine, but my question is does crimping or non crimping have an effect on accuracy?

  • #2
    Originally posted by Otis" post=18072
    I understand why you crimp a 30-30 round when using tubular magazine, but my question is does crimping or non crimping have an effect on accuracy?
    Crimp for your leaver gun.

    Crimping stops the bullet from getting pushed back further into the case while the gun is under recoil. You don't need a excessive crimp.

    Crimping also increases the pressure for that nano second. Before it heads down the rifling. Where as the no crimped will start heading down the rifling as soon as there is pressure to push the pill.

    If you can do a consitant crimp then your Accracy should be slightly better ( due to the pressure build up prior to the bullet heading down the rifling, ( better consistent FPS ) . Then over non-crimped. A leaver gun is not a bench gun so never expect that its going to print 5 rounds in a 5c peice. At 100.

    In short crimped Yes will improve your groupings.

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    • Guest's Avatar
      Guest commented
      Editing a comment
      Thanks for that

  • #3
    Just to be different

    I don't crimp mine, no reason just can't be bothered. I find that reloading with Hornady Leverevolution pills, the accuracy is good enough ie 2 inch groups at 100 yards.

    That's good enough to drop piggies for me

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    • PKFFW
      PKFFW commented
      Editing a comment
      Originally posted by Bricktop" post=18098
      Just to be different

      I don't crimp mine, no reason just can't be bothered. I find that reloading with Hornady Leverevolution pills, the accuracy is good enough ie 2 inch groups at 100 yards.

      That's good enough to drop piggies for me
      Since you are the only one I have come across that reloads the leverevolution ammo I hope you wouldn't mind answering a few questions.

      How much does it cost you to reload the Leverevolution ammo?
      What the average cost saving per round is?
      What would be a ball park figure for setting up all the reloading equipment?

      Many thanks.

  • #4
    Hi...

    I crimp to stop stove piping. If the added benefit is a little better performance, great. Its better than cleaning up a mess.

    My lever actions are not bench rest accurate, they were never meant for that.

    Paul

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    • Guest's Avatar
      Guest commented
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      Originally posted by paul" post=18133
      Hi...

      I crimp to stop stove piping. If the added benefit is a little better performance, great. Its better than cleaning up a mess.

      My lever actions are not bench rest accurate, they were never meant for that.

      Paul
      I don't follow ( stove piping )Why would crimping or non crimping save you on cleaning, its all going pretty much in the same direction is an it??

  • #5
    Just another vote for not crimping sometimes. The caveat being that I shoot mild cast bullet loads and only load a few in the magazine at the time. If I was charging through the bush and shooting factory velocity rounds I would crimp to avoid the telescoping problem.

    The accuracy question is moot - do benchrest shooters crimp? Certainly consistent neck tension is very important for accuracy however is this more a feature of neck thickness, concentricity and size of expanding bell?

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    • #6
      OP
      Originally posted by Otis" post=18072
      I understand why you crimp a 30-30 round when using tubular magazine, but my question is does crimping or non crimping have an effect on accuracy?
      YES crimping can effect accuracy..

      First you have to understand the types of crimp and how a round is crimped, you have;
      • Factory or rolled crimp
      • Collet crimp
      • tapered crimp, used on Pistol Rounds using lead projectiles.
      Main reasons for crimping is
      1. To stop the projectile sliding back into the case
      2. To provide a better water tight seal on the case
      Increasing the case pressure is a secondary reason one of personal choice.
      Uniformly crimping cases requires experience with many process variables that can dramatically effect accuracy.
      Also keep in mind the more times you crimp brass it goes harder faster damaging the case neck when fired resulting in lower No. of reloads.

      The main types of crimps for rifle and Pistol is the rolled or collet Crimp

      The first cartridge, left above, does not engage the bullet's cannelure. The second is rolled into the cannelure at the top edge, but does not engage the bottom edge of the cannelure, the collet crimp is pressed into the cannelure groove with lateral force applied about the bullet's circumference and engages both top and bottom edge of the cannelure; none can be considered minor differences.

      Tapered Crimp for Pistol using lead projectiles
      This is the best crimp used for reloading pistol ammunition for accuracy.

      This is the best image i could find to depict tapered crimp..

      The tapered crimp is used to return the bell or flare after inserting a lead projectile.
      you do not want to actually crimp the projectile just return the neck to the correct parallel diameter.

      To achieve maximum accuracy use the same type of brass from the same batch fired the same no. of times to maintain consistent brass hardness.
      clean your cases before reloading to remove carbon buildup inside the case particularly in the neck are that of the case that contacts the projectile.
      Checking case length is another factor in crimping to be mindful of.
      This will maintain consistent tension on the projectile between rounds resulting in a uniform burn/pressure and release of the projectile from the case.

      Crimping to save $$$ by increasing pressure/velocity because you use less propellant is a personal choice, not one i would practice.
      Also crimping is not the fix for stove pipes and other ejection issues.

      [i]Reff:
      http://www.exteriorballistics.com/reloadbasics/crimp.cfm
      http://www.realguns.com/Commentary/comar184.htm
      http://www.realguns.com/Commentary/comar64.htm

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      • #7
        I'd be concerned about not crimping the rounds in a tubular magazine.

        Bullet setback, where the projectile is pushed into the case can lead to increased pressures.
        The theory is that you take a set amount of fuel, ignite it in a certain space, it will produce a given pressure. Then you change one thing; make the space smaller, pressure rises.
        ---------------------------------------------------------------------------------------
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        Where we are, where we belong, where we should be.

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        • #8
          If I don't crimp my 30-30 bullets, the tube magazine spring alone is enough to push in one or two bullets. Even with a crimp, I'll get 1 in 20 that scrapes past the crimping groove anyway, which is why I "push test" all my handloads with my thumb.

          It's not the spring tension itself; It's when the lifter drops into place at the base of the magazine, which opens and a 30-30 round drops down onto the lifter. The round has its own length to fall, which is enough to jolt a few bullets into their cases back in the magazine.

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          • PKFFW
            PKFFW commented
            Editing a comment
            I've never reloaded so forgive me if this is a silly question but how much effort does it take to crimp each round? If it's a quick and easy process why not do it "just in case"?
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