Keyholing Bullets

Discussion in 'P-3AT' started by Ka6otm, Aug 7, 2010.

  1. Ka6otm

    Ka6otm New Member

    Sep 12, 2007
    Had an interesting time at the range Thursday. I started out shooting handloads in the P3AT as usual for my warmup. Ran around 6 or rounds through it and they were clustered nicely an inch or so left of the bullseye "X" and dead on for elevation and then I loaded up a second magazine and...

    Bam, one hit around 8" lower than the others. Hmmm. Fired another and it hit 8" low also and close to the other low one. Pulled the target in and checked it and both bullets had keyholed.

    By then the wife had rounded up the two latest empties from the next zipcode and brought them to me. Both of them had splits going from the case mouth to about halfway down the case.

    Fired the remaining 4 in the magazine and they clustered with the other 6 around the bullseye.

    I never knew that a case split would make a round keyhole like that. One of them was totally sideways from looking at the target and the other was partially sideways.

    These were a mild load, 2.7 grains of Unique and definitely had less recoil than WWB or Hydrashocks so they weren't overloads. However, it was around the 6th firing for those cases.

    You learn something new every day I suppose.
  2. oldgranpa

    oldgranpa New Member

    Sep 23, 2004
    That is interesting. Cases must have let go on firing and the resulting pressure drop gave a very slow velocity (evidence the bullet drop on the target). So the bullet began to tumble giving you a 'keyhole'.

    During testing of a 2" barrel SeeCamp 380 pistol, a friend and I got keyholing with almost all brands of ammo we tried. Just that short barrel never got the bullet spinning and stabilized in flight.

    Better check that brass before you reload anymore of it.

    og...who will never buy a 380 pistol with less than a 2.5" barrel.