Not to muddy the waters any, but IF you mix brass and steel case ammo, not much in the way of good can happen.
I have shot close to 1000 rounds of steel case, mostly Bear, and several hundred rounds of brass, all Federal Green tip. And I always shoot the brass first. Steel does not expand like brass and can leave the chamber fouled and that in turn can create higher pressure and difficulty to extract. Just thinking out loud. IF you have an ammo problem, it helps to identify the brand, lot and bullet type.

Is anybody starting to smell something funny???

All i know.... is I have learned ALOT from this thread and the other One that was Re-Posted


Anytime now that I may have an issue with my AR round Not Loading, or ejecting... I will for sure take 2 minutes to Check the Barrel and just BE SURE nothing has Happened......

I run my Slide fire on my M&P Sport... and had my 1st ejection Issue last week........ Next Time....... I will take the extra Minute and just be sure all is Good... i did that time but did not look Down the barrel..... i will if it happens again... I also have some Factory rounds, only like 40, on striper clips for fast loading... may even stop that as well... maybe just do that the night before or something.. or toss the boxes in a box till thet are all shot....


This is a tragic and unfortunate incident... thankfully no-one was hurt.....

But i for one have learned from it

.............

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--Stav--

stavman11...I am in total agrreance...this whole situation has taught me a lot .It's unfortunate that it happened to anyone in the first place,but. it's always a good thing if yourself and others can learn from it.

Wow, this train wreck is still topping the charts?
I nominate we change gsochallenger's name to Pinata.
Everyone has taken a swing at him, most have hit, and he's still swinging in the breeze.

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Hold my beer and watch this!

update. after quite a few calls I finally got my rifle back. they had disassembled it. sent me a letter offering me another rifle at dealer cost even though the lower is in perfect shape. oh and the letter says it was a over pressure round and that no case was removed but its not in the rifle. when I talked to them yesterday asking where was the casing and how the casing dissappeared. Of course the guy thats over CS told me he needed to look into why the casing was not returned and why Kate the CS manager claimed that it wasnt in the rifle. I was supposed to hear back from him yesterday, but that didnt happen.

Did you take a picture of the casing? It isn't appearing in your pics that I can see. Are you sure you had it in the aftermath of the explosion?

I didnt disassemble the rifle. The bolt was lodged in the receiver, so unless the complete casing vaporized............

Gso,

That sucks that S&W didn't return the remnants of the casing. I'm also a bit disappointed in the way that S&W CS is handling your requests.

If I had to deal with an already agitated customer, I'd make sure that the small easily accomplished tasks such as timely customer contact were taken care of.

__________________
-John

At least you got your rifle back.

I'll give ya twenty bucks for the rail!

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Rod
M&P 22A, 40c, 15A, 15-22

After looking at your pictures I believe the upper was not manufactured by S&W. Not too long ago I put together a
rifle that had a mp15 lower and an unknown upper. He bought the pieces at a gun show. I put the springs and pins in the lower and when I went to fire it and it fired only once and did not cock the hammer.

I had to wire wheel the parts that did not fit just right. The old rule of mil spec should fit all mil spec is a fantasy.

The upper you have was due to faulty manufacturing not a hot load.

Granted, I'm pretty new to the world of AR's, only having my Sport for about a year, but I think that if the OP's upper was NOT and S&W upper, that they would have figured that out during there inspection...

Its a correct S&W upper for the weapon. Aside from many reasons, if it had not been the correct upper for the weapon there would have been no offer from S&W for a reduced price on a new weapon.

The damage, well thats debatable it seems to some. To me its clear just based upon the pictures alone, but I will not go into it deeply as I don't have the time. I've seen the same thing happen with other AR platforms we have tested with 'fire to destuction' with over pressured ammo.

The focused point of damaged indicates explosive over pressure and not defect in manufacturing or materials. There are telling indications in the pictures where an over pressure explosion force breeched the material integrity causing it to fail. The main part of the explosion force exited the weapon towards the bottom of the bolt in its longitudinal lower right quadrant area away from the operator. The pictures show the source originated from the inside and moved outward, that is not consistent with material or manufacturing defect, it is consistent with an explosive source.

I can tell you exactly what happened, seen it a hundred times; The over pressure explosion occured, the main force first contact was directed into the bolt/BCG along its longitudinal axis. The BCG splits along the longitudinal axis, the pressure of this split driven by the explosion taking the path of least resistance towards the ejection port area bends the front of the BCG out contacting the material at the front ejection port area placing sudden impact pressure at that area. The position of the split part of the BCG is now outward with the expanding explosion behind it but this part of the BCG partially traps the explosion force and re-directs it towards the material at the front ejection port where the explosion force now forces the metal outward above and below the edges of the BCG split. This material has already been weakened by the BCG split portion slamming into and placing pressure upon it. The metal gives way as the explosion pressure also hits it, with the combined forces the metal breaks and splits away from the main body. All this is consistent with a sudden explosive over pressure situation. I agree with the S&W assessment.

Doesn't matter much now as to what happened that caused this in the first place, its done. Its been over 60 days since the Op posted this experience, and I'm assuming that he has already resolved the situation with S&W.

OP sorry about your luck. I know I'm beating a dead horse, but is Wolf ammo in that bin, or any other steel cased round?

Some of the M&P rifle specs only list the 5.56 rounds.

I could be mistaken but I though .223 can be a higher pressure? Could that pressure difference between .223 and 5.56 be significant enough of a difference to cause this type of damage?

Can't really say without inspecting the case because we don't know what he was actually using for ammo and neither did he. Normally Nato 5.56 has higher pressure than .223. The Op said that he did not use reloads, but if he was using re-manufactured then he was using reloads. All of that really cheap stuff people buy are mostly "re-manufactured". So what ever he was using produced pressures that greatly exceeded the pressure of the standard 5.56 Nato round. The model in his pictures is the M&P15T - 5.56 mm Tactical.

The other way around.

I'm guessing something like this happened ---> YouTube - Broadcast Yourself.

Reguardless,it'd still be nice to know what his outcome was.

I will be keeping my SIG556 rifle. Pete

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NRA LIFE 1974