Help with crimp please

[JS22]

Been reloading with my 550 a little over a month now for cowboy action. Been using Trailboss and several different bullet styles and weights. So far they have all gone bang without incident. ( approx. 500 rounds ) Today I received a different stlye bullet and had to adjust for COL. I have read several post on many different forums about proper crimp. I have read that too much crimp may cause excess pressure, not enough allows gas to escape. Can someone please tell me the correct way to crimp. Until now I have adjusted the die down until the round will fit into my case gauge.

[redwoods]

I also shoot cowboy action.....38 special ruger vaqueros, and a Marlin 1894 cowboy comp. in 38 also.

When I get new bullets, (lead) I seat them till the lube groove is covered and then just a little bit more....you may have some cases that are taller, shorter, than others, so you need some play in there. If you read the instructions on your dies, they will tell you to pull the press handle all the way down, screw the die down till it stops on top of the bullet, then raise the handle and turn the die down 1/4 to 1/2 turn. I normally go with 1/2 to 3/4 turn. To feed in your lever rifle gun, you should have at least a normal crimp which will help it feed best.

Randy

[G-ManBart]

Been reloading with my 550 a little over a month now for cowboy action. Been using Trailboss and several different bullet styles and weights. So far they have all gone bang without incident. ( approx. 500 rounds ) Today I received a different stlye bullet and had to adjust for COL. I have read several post on many different forums about proper crimp. I have read that too much crimp may cause excess pressure, not enough allows gas to escape. Can someone please tell me the correct way to crimp. Until now I have adjusted the die down until the round will fit into my case gauge.

Don't take this the wrong way, but you really need to buy a reloading guide and read up on what you're doing.

What cartridge are you loading for? What bullet are you using? Does it have a cannelure?

Generally speaking a little bit too much crimp isn't going to cause excessive pressures, or even elevated pressures. It will overwork the brass and cause the case mouth to split earlier, and it might hurt accuracy, but not likely to cause a significant problem....you're have to really be on the edge already to cause that.

For light loads like CAS stuff, you don't need a heavy crimp that is used to prevent the bullets from moving forward under recoil (can jam the cylinder). Just barely rolling the mouth into the cannelure, or firmly pushing against the bullet if no cannelure is probably going to be fine. R,

[Rufftytuffty]

I use 1/32 (or 1mm) of visible crimp for both my 45ACP and 308 as both are magazine fed.

Dunno anything about cowboy action...sry.

~Mike

Edited February 11, 2010 by Rufftytuffty

[dillon]

For CAS, you must be using a lead bullet. If the bullet has a crimp groove-not to be confused with the lube groove, which is usually full of colored wax- seat the bullet until only the top of the groove is visible, usually .010"-.015". For crimp adjustment, you need to slightly curl the case mouth into this crimp groove. To test for sufficient crimp, if you can run the edge of your thumbnail down the side of the bullet and over the crimp, your nail should not catch on the crimp. This works regardless of caliber.