Neck turning and magazines?

Discussion in 'Reloading' started by KiloTango, Jul 7, 2013.

  1. KiloTango

    KiloTango Active Member

    Feb 16, 2013
    How thin can you turn a case neck before it becomes an issue for a magazine fed bolt action rifle with regards to reliability and bullets not keeping a consistent OAL?

  2. JeffVN

    JeffVN Well-Known Member

    Mar 19, 2004
    I run all my neck-turned rigs at 0.012, with 0.002 neck tension. None have suffered from bolt action magazine-induced bullet set back. (0.002 is probably not enough neck tension if you are running an AR or similar gas/piston-driven system)

    If set-back is your concern, I suspect neck-tension is more critical than neck thickness.


  3. SidecarFlip

    SidecarFlip Well-Known Member

    Dec 12, 2011
    My rule of thumb is crimp the pill in the neck if in doubt.

    However, the crimp compression entirely depends on the end use, in other words, a gas blowback action would require a more agressive crimp than a bolt action and where you carry the ammunition (in your hunting jacket pocket on a hunt as an example and the weight of the pill versus the neck tension), also determines the crimp amount.

    I use Lee collet crimpers exclusively. Reason being is I can control the amount of crimp, from almost nothing to actually crimping the pill without a cannulere.

    Keep in mind that 99% of factory ammunition you purchase is crimped because the factory has no idea how it will be stored or handled or what it's used in by the end user.

    Finally, I've never experienced any excessive pressure signs in hotter loads crimper versus not crimped. If it's loaded hot and pressure signs develop, it don't seem to matter if the cartridge is crimped or not....

    Just my opinion and the way I reload.
  4. c_bass16

    c_bass16 Well-Known Member

    Sep 22, 2009
    I just started loading my first true LR bolt gun and my Nosler Comp brass is .015 with .003 neck tension.
    I agree that I'm not sure the thickness matters as much as the consistency of the thickness.

    What kind of variance do you guys see with thickness?
    I've only found +/- .001 in variance in thickness among this lot of brass, and that didn't seem significant enough to justify the cost of cleaning them up at all.