crimping

[colt1911fan]

i heard that you have to crimp autoloading pistol rounds different than revolver rounds or the bullet will go into the casing is this true and how much more do you have to crimp them

 

[Grumulkin]

Any straight walled rimless case that needs to be crimped has to be taper crimped because the case headspaces on the mouth of the case. You can use any type of crimp that you like on rimed, bottle necked or belted cases. In the case of most autoladers like 9mm, 45 Auto and the like, I wouldn't crimp at all.

 

[cdrt]

Grumulkin

In the case of most autoladers like 9mm, 45 Auto and the like, I wouldn't crimp at all.

Did you mean you would not roll crimp, since you stated autoloader rounds should be taper crimped?

Navy Vet & SWIFT Boat OIC

 

[benedict1]

I disagree on not crimping autoloader ammo. I use the Lee Factory Crimp Die and put a taper crimp on all the 9mm and .45 ACP I load. If you expand the case mouth much at all to seat the bullet you will have problems. Once in a great while I'll forget to put that factory taper crimp on a round and it is pretty certain it won't chamber.

For revolver ammo I use the Lee Factory Crimp Dies too but make a roll crimp to prevent bullet setback.

 

[Walkalong]

You need to a least remove any belling with the taper crimp die. I go a slight bit further with the .45, but my crimp is so slight it is hard to see with the naked eye.

 

[GRIZ22]

I taper crimp auto ammo and roll crimp revolver.

 

[Grumulkin]

Did you mean you would not roll crimp, since you stated autoloader rounds should be taper crimped?

If a straight walled rimless cartridge is to be fired in an autoloader or other gun holding more than one cartridge and if it is to be crimped at all, it should be taper crimped and not roll crimped. They don't necessairly have to be crimped though.

I taper crimp 50 AE because it's a fairly high recoil round. I wouldn't crimp rounds with fairly light recoil but it doesn't hurt to do so. As regards removing the belling of the case with a taper crimp; I agree with that if you've put much bell on the case. I bell my straight walled cases just enough to get the base of the bullet started and no more so I don't need to compress the mouth of the case to get the round to chamber.

Some feel that crimping results in more consistent and reliable powder ignition. I haven't found this to be the case. In my opinion, the only reason to crimp a cartridges is to make it more durable; in other words to keep the bullet from moving in a magazine when the gun is fired or when the cartridge is banged around.

 

[Idano]

I agree that straight wall cartridges need just enough of a taper crimp to straighten walls of the case after seating the bullet. Large caliber revolver and rifle cartridges need to be roll crimped so the bullets in the cylinder or magazine don't move during recoil. However, all other cartridges I would never crimp because it doesn't do anything more then increase the wear on your brass and affect your accuracy IMO.

 

[Matt Dillon]

I would roll crimp .38 special and .357 Magnums (and other straight walled revolver cartridges), use the Lee Factory Crimp Die on rounds like .380 ACP, .40S&W, and .32 ACP, and use no crimp at all on rifle rounds that are loaded into bolt rifles, otherwise, if they are semiautomatic rifles, you should crimp them with the Lee crimp die.