M&P-15T Malfunction?

xHUSKERx

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So tonight after cleaning my gun I was doing a operations check on the gun. When I attempted to chamber a round it took a couple tries and finally one went in (think it was a mag problem) but then my bolt didn't completely close and when I attempted to clear the round it would not come back out but was stuck in my in the gun in the star chamber (not sure if that's what it is called) Had to mortar the rifle to get the bad boy out.

I keep a very oiled AR perhaps a little to much, don't know if that would cause this problem, maybe a problem with that round. Never had this happened before and I really don't think it is my AR, in the first week I have had it I have put 500 round through it with 0 problems besides mag related things.

Any help determining the cause of this and any tips would be greatly appreciated thanks. After further inspection i think this may have been caused by way to much oil,seems to have collected in my star chambers. Is that a probable cause.
 
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You were function checking your rifle with a live round or a snap cap?

When storing the rifle, a light coat of oil in the chamber and lugs is ok. Before going to the range, swab out any excess oil from the chamber and run a couple dry patches down the bore. Excessive oil in the chamber and/or bore can cause a pressure spike leading to a catastrophic failure.

When you attempted to chamber a round, how did you do it? Did you ride the charging handle? Did you lock the BCG back, insert the mag, then use the bolt release?
 
I am not sure what you mean by "star chamber", but if the round was partially chambered, and the ejector had a grip on it, but it was difficult to pull the charging handle back and eject the round, then it sounds like an out of spec round. A little to much oil will not hurt anything, and some guys like to run their AR's wet.

Larry
 
He described the chamber lugs. Round got caught up. I suspect an out of spec round.

BCG wet = OK

Chamber & bore wet = No

Also of concern is performing a post cleaning and inspection function check with a live round and not a snap cap or inert round (no primer or powder).

But this is just me... If you want to live dangerously function checking with live ammo and running a chamber and bore wet, go for it.
 
JaPes you have helped me alot thank you.To clarify my BCG is wet but my bore and chamber I keep dry, even inspect before I ever shoot and dry it out if need be.

I am not sure what I did but perhaps I rode the handle I am not sure. I was not checking with a snap cap, I don't fire the live round but I broke my dummy round I had so I didn't have another way to test. Not doing that again, live round stuck while not at the range scared the piss out of me.

I believe and out of spec round was the cause as well, I checked the BCG and everything seems find, just had some excess oil on it so I cleaned it.
 
When I got my first ar the guy at my lgs said "you gotta run it wet." So I went home cleaned it good and hosed her down. Same exact thing happened,knocked it out with my cleaning rod and noticed the bullet was covered in oil.I put 2&2 together and figured two things out. That guy was full of **** and to much oil can actually create a suction effect thus causing the round to stick. Japes said it,bcg-wet the rest just a little will do.
 
How can I check the extractor on it? I will be taking her completely apart tomorrow to get rid of the excess oil, I use remoil and am unsure how much is enough for my BCG, i think some of it was seeping into the chamber.
 
I don't see chambering a live round as a big deal, as long as other safety rules are followed, such as finger off of trigger, and firearm pointed in a safe direction.

I doubt it was an out of spec round. I think it was a combination of too much oil and riding the charging handle forward. Too much oil can cause issues too.
 
Well whenever I was trying to chamber the first time I didn't ride and it didn't chamber, second time I rode it to see why it wasnt engaging and the round seemed to be "slipping" and the bolt was engaging it. Like dragon said when I took it out the thing was coated in oil. Either way I will clean it and do a full check tomorrow.
 
then my bolt didn't completely close and when I attempted to clear the round it would not come back out but was stuck in my in the gun

As the bolt closes, the extractor(7) has to ride over the rim of the round. If the extractor does not move over the rim, the bolt will not close, and the round will be left in the chamber.

Another possibility. Item number 6 is the ejector. It has to move freely in and out. It is spring loaded, but if it binds it could also cause the round not to seat completely.


bolt-assembly_2bd799e9-db36-4f08-87ad-420279bb6d11.gif
 
Never cycle live rounds through your weapon to do a check on them.
Ever hear the term slam fire. You are asking for trouble doing this.. Please use safe gun practice. Take it to the range and shoot it to find out if it functions properly.
 
I hear ya Dino, I know what they are and I am glad it didn't happen but with the location I was at there was no danger at the time. I was in a rural area with the next house being miles away, gun pointed away from any person. But I totally agree.

Quaker I suppose the excess of oil may have caused the ejector to gunk up because it was not moving freely when I tried to compress it.

I will soak my bcg pieces in hoppes tomorrow to get em moving again.
 
JaPes I have had it happen once before old .22 didnt load the round all the way into the barrel and it blew up in my face and the bullet went out the side, luckily no one was hurt but I couldn't hear out of my right ear for about a day.

You weren't being grouchy just informative, safety ain't no joke.
 
You were function checking your rifle with a live round or a snap cap?

When storing the rifle, a light coat of oil in the chamber and lugs is ok. Before going to the range, swab out any excess oil from the chamber and run a couple dry patches down the bore. Excessive oil in the chamber and/or bore can cause a pressure spike leading to a catastrophic failure.

When you attempted to chamber a round, how did you do it? Did you ride the charging handle? Did you lock the BCG back, insert the mag, then use the bolt release?

Live Round??? dumb, dumb, dumb, I have a friend who, had an AD recently with his M&P, we shoot together, and he is a great shot with good gun manners generally,,,,, but after I handed him my 3913 LS, he fired one round, and after the loooong, first round DA pull, he pulled off the target and was "observing" the weapon, holding the gun sideways where he could see it, finger still on the trigger, and I'm thinkin, here comes an AD, and "BOOM", sho nuff. I slapped him around, he went back to his M&P 9, and had a couple of Failure to Feeds, with the live round hanging out of the chamber, wouldn't go in, and wouldn't come out, finger "still" on the trigger as he attempted to "clear" his weapon..I slapped him around some more. KEEP YOUR FINGER OF THE TRIGGER, it will be bad, DON'T TOUCH IT!

So, your mag is likely a little wonkey??? you likely "bobbled your reload", your brain was prolly telling you "NOT TO CHAMBER" a live round for a function check. Now JaPes, oil in the chamber or barrel will likely cause pressure to go up, but the only "catastrophic" event I have personally observed with an AR is an "out of battery discharge" are you suggesting that an AR in 5.56 that is fully in battery is going to, go "Kabloooii", because of excess oil in the chamber or barrel???

any out of battery event, with any weapon has the potential for serious injury or property damage, but a 223/5.56 is very well contained in an AR type weapon, as long as it is fully in battery, the exception might be a solid bore obstruction such as mud or a squib, with the bullet stuck in the barrel???
 
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Live Round??? dumb, dumb, dumb, I have a friend who, had an AD recently with his M&P, we shoot together, and he is a great shot with good gun manners generally,,,,, but after I handed him my 3913 LS, he fired one round, and after the loooong, first round DA pull, he pulled off the target and was "observing" the weapon, holding the gun sideways where he could see it, finger still on the trigger, and I'm thinkin, here comes an AD, and "BOOM", sho nuff. I slapped him around, he went back to his M&P 9, and had a couple of Failure to Feeds, with the live round hanging out of the chamber, wouldn't go in, and wouldn't come out, finger "still" on the trigger as he attempted to "clear" his weapon..I slapped him around some more. KEEP YOUR FINGER OF THE TRIGGER, it will be bad, DON'T TOUCH IT!

You need new shooting buddies. This one is an accident waiting to happen.
 
Yeah, but that's his buddy. Better to attempt to address and correct his behavior, than not. I'd hate it if I had a buddy that I knew to be severely deficient in handgun & range safety, didn't try to correct it, and that buddy dies or is grievously injured. I'd rather my conscience be clear.
 
Now JaPes, oil in the chamber or barrel will likely cause pressure to go up, ... are you suggesting that an AR in 5.56 that is fully in battery is going to, go "Kabloooii", because of excess oil in the chamber or barrel???

Yes. Excessive oil in a chamber and bore can possibly create conditions conducive catastrophic failure. I am no expert. I only understand the concepts in layman terms. Think water hammer in a steam system. The possibility that the excessive oil can pool in the barrel. Because the oil does not rapidly compress, the bullet/gas slams into the oil... barrel ring or KB. Excessive oil in the chamber can cause projectile set-back, increasing pressure.

While the probability is low that all the causal factors converge to cause a catastrophic failure is low, the probability still exists. This is why I always advocate that prior to a range trip; swab out the chamber with a dry patch and run a couple dry patches down the bore to remove excessive oil. That will leave a light film of oil that is fine. The cost of a few patches and a 5 minutes of time is worth it to me to lower the probability of catastrophic failure.

It's tax-refund season. I'm sure there will be a fresh crop of brand new AR-15 enthusiasts joining the forum. I try to remember that not everyone here has the same background experience in which to put some of the phrases and lingo used here into context. When new people to the AR-15 hear that the AR-15 likes to be run really wet, they have no frame of reference as to what that means. Running the BCG "wet" isn't a big deal. A new AR-15 enthusiast may make the false assumption that if the AR-15 likes to be run wet, that means BCG, Chamber, Bore.

The other thing I want any brand new AR-15 owner to understand is that the range is one-way. No one is shooting back at you. You have the luxury of time. You can take the time to inspect and prep your rifle prior to a range session. If you experience a malfunction at the range, you have the luxury of time to stop shooting, get assistance in diagnosing the malfunction in order to employ the correct remediation procedure.

If anyone is curious as to why I always do my best to err on the side of caution:

KB2.jpg


That was my own fault. My inattentiveness before and during a session at the range combined to cause this. When I was shooting the rounds in the cylinder, the recoil impulse didn't feel right. Like an idiot, I did not listen to my gut feeling, stop, and assess. I don't want anyone to have to learn the lesson the hard way like I did.
 
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