Yesterday's Weapons Forums

Pete:

I didn't mention the pistol headspace gauges and probably should have.

These help the reloader determine proper case length for their pistol cases, and if they need trimming.

Another use for the pistol gauge is to check loaded rounds to see if they are within SAAMI specs to fit in a chamber. Sometimes things like bullet bulge in the side of the case will prevent chambering. If you've ever tried to use Amerc brass, for instance, it is often thick enough that with a bullet seated it will not chamber.

Pistol cases typically don't need trimming as often as bottle-necked rifle cases. The reason is simple. The straight walls of the case are not subjected to near as much force from pressure when the load goes off.

Pistol cases that headspace on the mouth of the case need more attention than rimmed cases. In this category are .32 ACP, .380 ACP, 9mm P, .40 S&W, .45 ACP and others. If the cases are too long in these calibers, the action will fail to go into battery and immediate action to clear it will be necessary.