Crimping Ar Loads

[milo 2.0]

Do you guys crimp your AR-15 loads? Normally I do not.
But in the past year I've seen 2 ar's blown apart, one in particular believes it was caused by the bullet being shoved back into the case during seating in the chamber.
I don't know if I buy this theory, but it is possible.

I just bought a pile of Hornady 68gr BTHP's with a cannelur,
would it be ok to roll crimp them with a standard seating die, or would one be worried about a pressure spike?
Any help would be great.
Milo

 

[427Cobra]

Re: Crimping Ar Loads

I use a Lee Factory Crimp Die, IMHO it's good insurance.

 

[kraigWY]

Re: Crimping Ar Loads

I have never crimped a 223 round in the 35+ years I've been loading 223s.

However, RCBS has made a speciel set of reloading dies that put a taper crimp on the necks to prevent what you refer too.

I'm seriously thinking of picking up and trying that die set, simply because it looks like it would make more consitant loads.

 

[milo 2.0]

Re: Crimping Ar Loads

Cobra,
The Lee is a collet crimp, leaving 3 symetrical imprints around the mouth, am I right?

 

[milo 2.0]

Re: Crimping Ar Loads

Kraig,
I do have a Redding taper crimp die, but your brass all have to be trimmed to close tolerances for it to work.
If not some get a heavy crimp, some none.
You and I need to hook up and do some shooting some day, we're not that far apart.
Miles

 

[105amatt]

Re: Crimping Ar Loads

i crimp mine. Just because I bought the 3 die set one sale, figured why not.

 

[427Cobra]

Re: Crimping Ar Loads

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: milo-2</div><div class="ubbcode-body">Cobra,
The Lee is a collet crimp, leaving 3 symetrical imprints around the mouth, am I right? </div></div>

It's a 4 prong collet, no marks on my brass at all.

 

[glock24]

Re: Crimping Ar Loads

Another Lee collet die user here.

With enough adjustment, I can get this die to leave marks on my brass, and even deform my bullets. However, I adjust it so that doesn't happen.

 

[Bearwalk]

Re: Crimping Ar Loads

I crimp everything, but it is not absolute protection against the incident the OP described. If a bullet is set too long and you slam a round home, the bullet will still likely get shoved back in the case....crimped or not.

That's been my experience anyway. FWIW.

But, in general this should be an accuracy issue....not a "go boom" issue. It has to be a really long bullet, relatively speaking, to get shoved far enough in to cause a dangererous event, especially in 223. Sounds to me like the bullet got shoved in well before the cycling of the action.

A crimp can also work against you if it does hold. Now you have really jammed that thing in to the lands which can also be a bad situation.

It should go without saying that make sure your load fits in your stick before calling it good.