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Case ruptured in my AR today

5K views 24 replies 16 participants last post by  charlie98 
#1 ·
I was out shooting my first 3-gun match today, used my 1911, EA-15, and a tactical 870. Midway through the match, I'm running through a stage and the next round I fire results in a black cloud around my face and powder burns down my left arm.

At first, I thought the gun exploded, but after looking at it I noticed that the case had ruptured in the chamber. The gasses were channeled down the magwell and left a nice powder burn on my left arm, I think I even drew in some shrapnel too because I had a few spots pooling blood. There's a rectangle the size of the base of an AR magazine of un-burnt skin and all around that is burnt. Looks pretty neat I have to admit GI2... Every round left in the magazine was covered in black residue and so was my arm.

The ammo was reloaded by a retailer that sells in bulk at the Crossroads gun shows. Bought it at a gun show in Vegas last December. It's 55gr FMJ in LC once fired brass, not sure about the powder. I think the entire 1000 round can is getting thrown out after this, or I'll pull the bullets and dump the rest. Not sure yet.

Nothing like this has ever happened to me before, I feel very lucky the gun didn't explode. Real eye opener.


Pictures will be up soon.
 
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#2 ·
Here's the brass.




The shot was on a 200 yard steel gong. and I still hit it. GI1



So could you tell me what caused it? Double charge? Wrong powder?
 
#3 ·
Years ago I had a batch of once fired brass I got from a brass supplier in Colorado that 2 out of the first 50 I shot ruptured on me. The magasines took the brunt each time. Needless to say I jiunked the remaining 1950.
 
#4 ·
Years ago I had a batch of brass I got from a brass supplier in Colorado that 2 out of the first 50 I shot ruptured on me. The magasines took the brunt each time. Needless to say I jiunked the remaining 1950.


Yup, I'm glad I had that magazine in.
 
#5 ·
My guess the same problem I had. Brass came from oversized machine gun chambers and overworked the brass in sizing. It was the same place where mine ruptured.

I was told later the brass supplier in Colorado readjusted their commercial sizer to not overworked the the brass. Did not matter to at that how they fixed I did not buy anymore from them.
 
#6 ·
Classic Casehead separation, imho.
Do you know how many times it was reloaded?
Do you know how it was resized?
Do you know what it was shot in?
Do you know the load consistency, reliability of powder charge?

Let the reloader know what happend in writing and keep a copy.

I'd recommend Black Hills Reman'd if you have a problem finding affordable, commercial loads. Or a friend into reloading who is VERY ANAL and you trust with your life.

Been there, done that:



In .308 it's even more exciting.
 
#8 ·
Classic Casehead separation, imho.
Do you know how many times it was reloaded?
Do you know how it was resized?
Do you know what it was shot in?
Do you know the load consistency, reliability of powder charge?

Let the reloader know what happend in writing and keep a copy.

I'd recommend Black Hills Reman'd if you have a problem finding affordable, commercial loads. Or a friend into reloading who is VERY ANAL and you trust with your life.
No idea. Bought it in a 1000rd can at a gun show from an out of state supplier. My guess is that its LC MG brass and was overworked.
 
#7 ·
I had similar happen to me with my M1A and some wolf ammo. Except I had full case head separation and I had to use a broken shell extractor to get the remaining part of the casing out of the chamber.

It was hot and dirty, and I'm glad I was wearing glasses but there was no long term effects.

I fired the rest of the 1000 rd case with no problems.

Maybe a flaw in the casing?
 
#9 ·
Does not look like it was overpressured, no primer extrusion. Case failure is more the case, possibly they missed an annealing step on a draw and it work hardend.
 
#12 ·
Sometimes you just get the case that fell off the turnip truck. We were firing the M24 the other day with LC M118LR, and I noticed two cases with split necks (only ones I noticed, out of 600+ rounds we expended total between 6 shooters). So, brand new ammo that's widely regarded for its quality can have case failures as well.

Glad to hear you came out relatively unscathed. I assume the only damage to your rifle was the magazine?
 
#13 ·
When the crack is around the case and where the head thins then it's normally a case head separation due to being re-sized too many times or too long of chamber headspace as compared to the case's headspace. That can happen by firing a properly sized case in a long headspace chamber or sizing the case too short and firing it in a good chamber. When the crack is down in to the thick part of the head then it's most commonly an indication of metal failure, a bad case from the manufacturer.

Your crack is exactly where the case thins as it stretches, my opinion is that it is an old, thin, FC case that has been fired before and was severely stretched and then you just happened to be the lucky guy that had it come apart for.
 
#14 ·
Federal brass has less case capacity then lake city. The brass used is not NATO spec either but I would guess it was loaded to 5.56 pressure. Federal brass can't be loaded hot or you'll get case head separation. I wonder what the powder was too; maybe a fast burner like H335 or WC844.

Shooting reloads can be very dangerous! If you buy them make sure you know the reload specs and then check to make sure they aren't too hot.
 
#18 ·
The people I bought it from mass produce reloads. I've bought thousands from them before, without a hiccup. At the gun shows, their booth isn't tables.... It's hundreds of ammo cans full of their reloads, and they sell away their lot in the show. LOL.
 
#23 ·
I'm still kickin' MCORPS1

I gotta admit though, it scared the Sh*t out of me for a few seconds haha.
 
#21 ·
Looking at your pictures, I can't see any indications of case stretch, primer shows no pressure problems, no indications of 'out-of-battery' fire and no visible indications of multiple reloadings. Case appears to have failed at the head wall which usually happens due to overworked brass (reloaded too many times), headspace to long (was your bolt/rifle headspaced by the factory, you or the builder?) or just a bad case. Chances are that you could fire the rest of the ammo and have no more problems.
Recommendations: Contact the ammo company and tell them what happened. A good, reliable company will correct the problem without questions or problems. Most companies carry insurance for such incidents and will replace the ammo left/repair damages if problems such as this occurs. Make sure you tell them about the circumstances leading up to the incident. Have a qualified, licensed gunsmith check the headspace and write a letter stating the headspace is within specs. This will be useful if further action needs to be taken. DO NOT dispose of the remaining ammo until you have received instructions from the company.
I had a case fail on me once and the company involved replaced the full purchase and the damaged parts on my rifle. But the incident did result in me getting into reloading for myself.
 
#24 ·
A lot of good info. Yes, I won't shoot anything reloaded by someone else, period! With that said, I've reloaded and shot thousands of rounds of FC brass, some 4, 5, or 6 times that feed 3 different AR's. I load for accuracy not max velocity. I've never had so much as a neck split let alone a base seperation. That doesn't maen I won't on the next shot however! :) I do anneal the crap out of them which I know many don't. I use a Lee Factory Crimp also. I have seen loose primer pockets but from what I've seen, if they aren't falling out loose, it isn't an issue. YMMV....O.L.
 
#25 ·
Yes, I won't shoot anything reloaded by someone else, period! .
I'm kind of right there with you on that. I shoot factory stuff and my reloads... that's it.

When I was stationed at Fort Carson back in the '80's, there was a gun shop in town that sold reloads of most common handgun rounds. You could trade in your brass towards more reloads... i.e., you brought in 50 .38spc cases, and you got a discount on another box of 50 .38 reloads... kind of like the old bottle deposits.

Who knows if your brass is just once-fired, or recovered brass from other ranges or what have you.

Shooting factory stuff isn't always a guarantee, either... I bought a case of Norinco 5.56mm, and about 1 of each 8 or 9 case necks split on firing. No other failures, but that opened my eyes a bit. I fired off the last of that ammo last year and scrapped all that brass... I was not taking any chances.
 
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