Is it normal for the cartridge overall length (COAL) to decrease after you put a roll crimp on the cartridge? I'm seating and crimping in two separate stages, and the overall length of the loaded round is decreasing by .005 or more, from 1.600" to 1.595" after I apply the crimp in the final stage. Is this a sign that I'm putting too much of a crimp on the bullet? Suggestions? BTW, the round is a .44 mag with a 240 gr. Hornady XTP with cannelure. Thanks.

Russell420

It would be normal for the rolling process of crimping to shorten the neck and move the bullet with it. For a 44 mag, what difference would you anticipate in the performance of the cartridge due to 0.005 difference in jump in a revolver or lever gun?

It's great that you noticed, but performance is in no way compromised. Revolver cartridges respond to COL only when the cylinder jams.

quote:

Originally posted by Winchester 69:
It would be normal for the rolling process of crimping to shorten the neck and move the bullet with it. For a 44 mag, what difference would you anticipate in the performance of the cartridge due to 0.005 difference in jump in a revolver or lever gun?

It's great that you noticed, but performance is in no way compromised. Revolver cartridges respond to COL only when the cylinder jams.

And if you seat all of your bullets to X length then back off the seater plug & crimp in a seperate step all your worrys will vanish
HAVE A GREAT NEW YEAR!!

Given that you worked up to this load (and you did, didn't you?) there should be no problems. As a general rule, a decrease in length will raise pressures, but .005" is nothing to be concerned about.
Secondly, without uniform case length, you can't possibly have uniform crimps. A lot of pistoleers I know overlook this simple fact until they have ignition problems with slow burning powders. The purpose of crimping is twofold: it holds bullets securely during recoil, and it helps ensure uniform ignition.

Thanks for the replies. TSturm, I am seating and crimping in separate stages. The COAL was decreasing even when doing it this way. Buckshot, yes, I worked up to the load in question and it is entirely safe. My cases were all trimmed to a uniform length after being full length resized, and the crimps were turned into the middle of the bullet cannelure. Thanks.

Russell420