AR reloading...no crimp?

[Elkins45]

My name rhymes with Ron. I don't crimp 223.

 

[carbine85]

Hi, My name is Keith and I go both ways, that is in crimping
I use the Lee factory crimp die on some loads. All it really does is squeeze the neck slightly for even neck tension. I don't roll crimp anymore.
If the brass is well used I don't see how crimping can hurt anything.

 

[GLOOB]

Can't hurt, maybe. I don't think the Lee FCD can help much, either. To prevent setback and bullet jump, the roll crimp seems like it should be superior.

All it really does is squeeze the neck slightly for even neck tension.

The sizer and expander ensures even neck tension. The Lee FCD ruins the neck tension where it presses at the casemouth in exchange for a sort of taper crimp. All forms of crimping reduce the neck tension under the area of the crimp. For pistol taper crimp, the only benefit is reduction of any excessive case mouth flare. For roll crimps, you're trading that neck tension for a mechanical fit that prevents bullet movement. With the Lee FCD, you are getting something sort of like a short and deep taper crimp that provides some mechanical fit, but not as much as with a roll crimp. I wouldn't trust it without some testing.

It might increase bullet hold a little, via the mechanical fit. So it may increase accuracy with certain loads/powders.

If you are having neck tension issues with your ammo, see my previous post.

 

[Okcafe86]

I don't crimp them but I'll check neck tension by pushing the bullet against my work bench every 25 rounds or so to make sure I have proper neck tension. No issues here.

 

[GLOOB]

See my previous posts. If you check one round out of 25, you can easily miss a round with bad neck tension. There's almost no point in spot checking for neck tension. Do it a few times when you get a new buillet or expander, just to make sure your expander and bullet are correct, then either stop or do it on every single round.

The bad rounds aren't caused by a misadjustment of your dies that you can just spot check every once in awhile. They are caused by the individual pieces of brass. You simply cannot feel the difference while seating the bullet; you can only detect cases with GROSSLY loose necks that will not even hold a bullet finger-tight. You can only reliably detect the bad cases when expanding. The expander ball is a perfect neck tension gauge. If you were going to build a tool to test proper neck sizing, it would pretty much be a .222 diameter ball on a stick - aka a ball expander. And gauging neck size is probably the best way to easily judge resultant neck tension in a "go / no-go" fashion. If you can push that .222" ball in/out of the case without resistance, that's a no-go. There are no additional steps, no additional equipment. Simply pay attention and feel the resistance while pulling the expander ball through the neck.

You can reload your entire life and never come across a case with a loose neck. But one day it might happen out of the blue. Hopefully, you will recognize it. If you are spot checking only 1 in 25 rounds, you will more than likely miss that case. And even if you find it, you may have 100's of finished rounds that you have to go back and test. Hopefully, you HAVE encountered a cracked case neck. During expanding, a loose neck will feel the same as a cracked neck.