This is something I'm sure we've all seen on relatively straight-walled cases for pistol and some rifle ammo. There will be a crimp applied, usually close to just behind the bullet. I'm wondering how they do it.

They are rolled on, usually after the round is assembled. You can buy a roll crimper aka canneluring tool, but they generally shorten case life--so avoid the practice unless you just cannot live without it.

quote:

Originally posted by Geo.:
They are rolled on, usually after the round is assembled. You can buy a roll crimper aka canneluring tool, but they generally shorten case life--so avoid the practice unless you just cannot live without it.

Yes, good advice.

AIR, the "just behind the bullet" cannelure was applied almost exclusively to straight-walled cases, and then primarily for ones which might be fired in tubular magazines where the back and forth motion of the cartridges, magazine spring, and magazine plug under recoil sometimes forced bullets deeper into the cases than they were originally loaded.

This was particularly applicable where the shooter kept refilling the magazine when less than completely empty...thus leaving the last couple of rounds or so in the magazine to be battered back and forth many times.