Crimping ?

Discussion in 'The Ammo & Reloading Forum' started by Todd 68, Mar 26, 2009.

  1. Todd 68

    Todd 68 New Member

    I have been reloading Rifle cartridges for some time but have never loaded any that requires crimping , I am starting my reloading adventure with pistols and my first one is a 45ACP. I was wondering if there was a way to gauge the amount of crimp that I use with my digital calipers . The man at the gun shop here told me that he had a paper at home that had the measurement for pistol crimping and I was wondering if any of you guys could tell me where I can get this info because I am looking at loading several differnt calibers and this info seems to be very important .
    Thanks Todd
  2. johnlives4christ

    johnlives4christ Former Guest

    Apr 28, 2008
    lyman reloading manual would tell you i think

  3. olmossbak

    olmossbak New Member

    Feb 12, 2009
    NE Tenn
    Don't crimp 45 acp with your bullet seating die. That ctg headspaces on the ctg rim and crimping (roll type) will result in misfires. There are taper crimp dies available for this purpose but I've never had to use them on any ctg developed for auto pistols.

    Revolver ctgs are a whole different matter as shooting the pistols will cause bullet creep and can cause the cylinder to jam in the frame. This is especially true in hot 357, 41, and 44mags. There are probably others. Most loading manuals will specify crimps on straight wall revolver ctgs. You also need to crimp rifle ctgs loaded for tubular mags.
  4. muddober

    muddober Active Member

    Sep 19, 2008
    Carson City Nevada
    Your 45 acp ammo should only be tapper crimped and not roll crimped as olmossbak pointed out. I will expand on that just a bit because I think he meant that case headspaces on the mouth of the case and not the "rim". Most but not all 45 acp bullet seating dies will only let you tapper crimp meaning you really can't see the crimp because of the tapper. While I have reloaded thousands of 45 acp I have never measured the very mouth of the case so that I can not tell you an actual measurement. When loading for a revolver (unless it is a 45 acp) you must always roll crimp the bullets to insure that they do not move forward during recoil of previously fired shots. I hope that helps.

    Last edited: Mar 27, 2009
  5. .001-.003 should be enough crimp. (That's thousandths)

    Measure the case where ther middle of the bullet rests. Then measure where the case edge meets the bullet. For .45 & most Semi-Auto ammo, you need just enough crimp to hold the bullet & have a smooth transition for the round to slide into the chamber. When you slide your finger from bullet down to the case, it should feel smooth. You'll still feel the transition, but not a abrubt edge.
  6. townmarshal

    townmarshal New Member

    Nov 29, 2008
    I've also found that with either taper or roll crimping, the oal can be up to
    .005 longer after crimping. Not a big deal but something to be aware of.
  7. JLA

    JLA Well-Known Member

    Feb 26, 2007
    Heart Of Texas
    crimping will almost always increase the consistency of your ammo. You will not notice a difference unless you shoot for accuracy and own a chrony though.
  8. Todd 68

    Todd 68 New Member

    Hey thanks guys I loaded some up for the first time last night and they shot good , I worked up some different loads and I got one batch to shoot 1 1/4 inches at 15 yards . I think that is pretty good for a home protection gun .
  9. JLA

    JLA Well-Known Member

    Feb 26, 2007
    Heart Of Texas
    what are you protecting your home from? rats? chihuahuas? large carnivorous insects??? 1.25 inches is well within the combat accuracy required for home protection. I use a 12 ga scattergun myself. I hate chihuahuas;)
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