Thread: .223 Ammo for AR, Crimp or Not

Working on some 223 ammo for our AR's with a friend. The question at hand is do we need to crimp the brass or not. My friend is an experienced reloader, but this is the first time he has reloaded for auto not bolt action. One bullet sunk back into the brass. Not sure if something else went wrong or if he needs a crimping die. Can anyone help us out?

Generally on any auto loader you need a crimp. I usually do mine as a final step. I seat in one station and crimp in the next vs doing it all at once. I have had much better results that way.

Originally Posted by Nwcid

Generally on any auto loader you need a crimp. I usually do mine as a final step. I seat in one station and crimp in the next vs doing it all at once. I have had much better results that way.

What kind of dies are you using? Is this a three or two die set?

They are 2 die sets but I am using a progressive press (but I do it in stages for rifle) so I have to use 2 dies at once, so I have an extra seater in a few calibers. If you are using a single stage press seat the bullet. Then when they are all seated adjust the die for crimp and run them all though again.

Yes you should crimp. I use Lee factory crimp dies.

+1 for crimping.. It can't hurt.....until one smashes there index finger into the die like a dumbass
Use the lee factory crimp myself..

Originally Posted by Nwcid

They are 2 die sets but I am using a progressive press (but I do it in stages for rifle) so I have to use 2 dies at once, so I have an extra seater in a few calibers. If you are using a single stage press seat the bullet. Then when they are all seated adjust the die for crimp and run them all though again.

Thanks a million. I really appreciate your help.

Do the bullets have a cannelure? If so, definitely crimp. If not, you may not gain anything if you do crimp unless you use a Lee Factory Crimp die to actually form somewhat of a cannelure.

If you're having issues with bullets being pushed back when cycling in an AR, check the feed ramps on the barrel extension (and lower if it's an M-4 style lower). If you have a miss-matched barrel and lower there can be an edge that can catch the tip of the bullet. Also check and see if it only happens with one particular mag. Bent feed lips can cause the bullet to be jambed because it doesn't sit high enough in the mag for proper feed. After mags are dropped a few times this can happen.

Back to the feed ramps, if the barrel is miss-matched to the lower, a little work with a Dremel can smooth it out so there is a "catch free" feed surface.

Yes, crimp with the lee factory crimp.

NO CRIMP I have researched the crimp or not to crimp question. I have reloaded many thousands of 223 for competition. I use a Dillon progressive with RCBS dies and fired from AR platform of rifles. If the case neck is properly sized the bullet will hold firm with no crimp. You should not be able to push it back into the case. I experimented with identical loads except for crimp and no crimp. Using a lee crimp die. Over the years I have tried this on many different loads and every time the no crimp would shoot half the group size! For years now I have loaded for my AR competition rifles with no crimp. I have had no feeding issues. Mostly use Winchester and some LC brass. Sierra 52,69,77 and 80 match king bullets.