What Would Cause This? (AR 15 Issue)

[Batteriesnare]

Took my AR to the range today (Stag Arms M4gery, 1/9 twist barrel marked 5.56) and I had a couple of significant ammo failures. The rifle had been completely stripped and detail cleaned last week and had not been shot since.

I was firing Winchester Q3131A that I bought from a fellow board member that appeared to be in good condition. After a few rounds I had a jam where the bolt would not close completely so I dropped the mag, cleared the rifle, and pulled back on the charging handle, locking the bolt in the rear most position. I then noticed that there were little metal star shaped objects just before the chamber. I dumped them into my hands and they appeared to be the innards of a primer. I then searched the brass on the ground, and sure enough, two empty cases were primerless. I immediately stripped the rifle looking for damage, and couldn't find any. I then reassembled and continued firing using UMC .223 without incident. I couldn't find any stress marks on the spent UMC cases.

What would cause this to happen? Was it just a bad piece of ammo, or should I avoid the rest of the ammo I purchased (500 rounds).

Thanks!

[Elhuero]

sounds like bad ammo to me, if it shot fine with a different brand.

occam's razor

if you're adventurous, pull out a few randoms of the winchester and try them.

[Richard K]

There was a post on the "other forum" about a bad batch of that ammo which caused high pressures.

[sniper7]

sounds like high pressure blowing the primers out. might be a primer issue as well. not sure. i dont think i would risk damage to your bolt. get the lot number and call winchester. hopefully you have the cases and the remaining ammo. take pictures. this is another reason i dont use winchester ammo or their components. ill post a link to my reloading data i did comparing hornady and winchester bullets. you would be amazed at the difference. glad you and your gun are all right

[low drag]

I know of 2 things that cause primers to pop out.

Over pressure ammo and out of spec primer pockets in the brass.

If you still have the brass can you measure the inside diameter of the primer pocket? The out of spec brass I had measured .177 while the stuff that worked fine measured .175

[theGinsue]

Are you certain that this ammo is factory and not reloads?

Something just doesn't sound quite right.

[bczandm]

Are you certain that this ammo is factory and not reloads?

Something just doesn't sound quite right.

I'ved used Q3131 and Q3131A for years and never had a problem. It's my favorite ammo. DON"T shoot any more ammo, from any mfg before the rifle is checked by someone who knows what they are doing. You and the rifle could be seriously harmed.

Have you shot the rifle before, without problems? It sounds like too high of pressure and I'd bet it's an ammo problem, but without knowing your rifle I'd get it check out. Something as simple as hot 5.56 in a .223 chamber can cause this (voice of experience).

In any event, on problems like these I like to error on the side of caution to prevent any serious injuries.
Bob

[MuzzleFlash]

Wonder if the firing pin could have pierced the primers during setback? Have you examined the firing pin and verified that it and the channel it lives in are free from grunge and crud?

[Batteriesnare]

Thanks all for the responses. Something just crashed outside the apartment so I'm awake.

A little more on the ammo:

I'm pretty sure its factory new. When I purchased it, it came in 20 round Winchester sealed boxes (just like the little white 5.56 boxes you find at Walmart.) The boxes are from batch SC62 and the blown cases are stamped from 2001. All individual boxes were factory sealed and in excellent condition.

Prior to purchase, I inquired as to the age, and the seller told me there were of older manufacture (new, not recent) and had been stored in water tight ammo cans with silicon moisture packs. I don't know if any of this changes anything, but I thought it may help. I'll see if I can track down a good digital camera in the next couple of days to take pics, all I have now is my webcam.

Muzzleflash:

I didn't notice anything strange on the bolt or firing pin after the incident. I'll do a more complete search tomorrow. Prior to firing it, I had completely stripped the bolt, cleaned the snot out of it, let it air dry for a day, properly lubed it and reassembled it, so there should not have been anything in the way. I'll take another look and post my findings tomorrow (today, whatever).



Thank you all again!

[sniper7]

If it is factory ammo like the guy claimed then I would call winchester with the lot number and also do a quick google search to see if anyone has had problems with that particular lot. If so that would make a good case against winchester to get them to send you some new ammo.

[Batteriesnare]

If it is factory ammo like the guy claimed then I would call winchester with the lot number and also do a quick google search to see if anyone has had problems with that particular lot. If so that would make a good case against winchester to get them to send you some new ammo.

Excellent sounds like a good plan, thank you!

[Batteriesnare]

Quick addition. Went back to the range after noticing I had two different lots. The WB30 is stamped 04, where as I received a few boxes of SC61, stamped 01. It was the SC61 that screwed up (bad powder was what I found online) the WB30 ran today without issue. Is it worth contacting Winchester over the 4 boxes I have left?

[rl45acp]

Bit off topic and I am not sure what "your" range is, but..
Batteriesnare: was taht you I saw up there yesterday (Tuesday)?

I was driving a lifted, white with peeling paint, old beat up GMC pick up. I got out an asked what you were shooting as I saw the AR being loadded into a Jeep. This was about 13:15.

Heh, small shooting world if it was you.

[sniper7]

Quick addition. Went back to the range after noticing I had two different lots. The WB30 is stamped 04, where as I received a few boxes of SC61, stamped 01. It was the SC61 that screwed up (bad powder was what I found online) the WB30 ran today without issue. Is it worth contacting Winchester over the 4 boxes I have left?


yeah I would call them and make them send me 4 new boxes of ammo. that is $40 of ammo give or take. They need to make it right.

[Batteriesnare]

Bit off topic and I am not sure what "your" range is, but..
Batteriesnare: was taht you I saw up there yesterday (Tuesday)?

I was driving a lifted, white with peeling paint, old beat up GMC pick up. I got out an asked what you were shooting as I saw the AR being loadded into a Jeep. This was about 13:15.

Heh, small shooting world if it was you.

I don't recall your vehicle, I don't have a jeep though, and I was wearing my plate carrying vest and had a bunch of steel set up. If it was, hello to you as well!

[rl45acp]

Nope, I don't think it was you then. I fugured it might have been, or at least another user here.

Sorry to bug ya. [Flower]



I don't recall your vehicle, I don't have a jeep though, and I was wearing my plate carrying vest and had a bunch of steel set up. If it was, hello to you as well!

[theGinsue]

Is it worth contacting Winchester over the 4 boxes I have left?

You're darned right it's worth it - on many levels. First off, you have to recoup your investment. I'm guessing that you purchased the ammo with hte intent to use it and with defective ammo, you can't use it. Secondly, you could have been injured and may have damaged your firearms because of their ammo - don't let it cost you any more than it already has. Lastly, you have to hold them accountable for their producing something that is sub-standard.

[Batteriesnare]

Thank you for the offer, I may have to take you up on that. I'm a little cautious to call Stag out on that, because all of their rifles are 5.56 chambered, and all are supposedly mil spec. Would you consider a Stag factory rifle to be "hobbist level"? (Just curious, you won't hurt my feelings)

Thanks!


There's another possibility. Too many barrels are actually .223 chambers, despite what the barrel may be marked. DPMS is notorious for this issue. As are other hobbist level weapons. Anyhow, this can lead to pressure spikes that pop primers.

Problem:
http://www.m-guns.com/tool_new.php?product=reamer

I have one of Ned's reamers, plus a plethora of AR tools. If you want the rifle looked over, let me know.

[jim02]

I have a Stag model 2 and have not hand any issues with shooting centurion, priv, silver bear, ultramax in 223 or 556. I vote this is an ammo issue not the rifle, you tested 2 other ammos and no issue, I say its the batch not the rifle at this point. See if Winchester will refund or replace the bad ammo.

[Littlebear]

Sorry to hear about your troubles, Chris.
I am "the guy" who sold the ammo. It was bougth from Jensen's a few years back and kept in an ammo can with a couple of large dessicant packs from the time I got it.
I did not handle the ammo in between and never noticed the two different lots.
You could contact Winchester and see what they have to say.

[Troublco]

I had a similar issue with some .300 Fireball that I had loaded for load development purposes. The brass was once fired that I processed normally and loaded up. I reached the point with pressure earlier than I had anticipated because I didn't consider that I was using mil brass when I loaded it, so I started popping primers sooner than I would normally expect. But in your case, I'd definately contact Winchester. Did they seem really hot? (Just curious.)