Ok So I was out at the hunting camp doing some target shooting with some friends this weekend and my S&W M&P AR was giving me some problems. I have had it for a few years and never had an issue with it until now....I would fire a round and then it would not fire. I cleared the chamber and it would fire again but still no follow up shots...I was also having an issue with the P-mags seating. no matter how hard you tried to slap it in the mag catch would not engage. Only when the bolt was retracted fully was i able to get a mag to seat correctly. I completely disassembled it there and cleaned everything and still the same issues.......Could one of you wise gentlemen please shear some of your knowledge and tell me what the possible problem is and what can be done to fix for it.....Thanks!.
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S&W M&P firing issue.....
- Thread starter firetug17
- Start date
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If the mags you were trying to seat were full, remove a few rounds then try again. Are they Gen 3 Pmags?
ksenter
Master
Mags seat with bolt locked back?
Marquezj16
Marksman
Is it ejecting the brass but not loading the next round? Is it doing it with just one magazine or all magazines? Is this a new Magpul or a ProMag magazine? They should never have to be forced in so hard. A light tap maybe but not to the point the mag catch would not engage.
Could you manually cycle a round? (Chamber a round and then pull on the charging handle. It should eject the round without difficulty.)
At the range or hunting camp - try this to diagnose the problem.
1. Use a different mag than the one that is not seating or a hard time seating. Load one round into the magazine, then insert to magwell. Chamber the round and fire at safe target. Does it eject the brass? Yes - then its not the extractor. No, then you have to see either a gas problem or extractor problem. Does it lock the bolt to the rear? Yes - no gas problem. No - then gas or cycling problem.
2. Using the same mag, load two rounds and insert into magwell. Chamber first round and fire at safe target. Does it eject the brass? Does it chamber the next round? If yes to both then it could be the magazine that was not cycling was the problem. If it shoots, ejects the brass but does not pick up the next round, then you either have a gas problem or something else is preventing the bolt from moving all the way back to pick up the next round.
Good luck.
Could you manually cycle a round? (Chamber a round and then pull on the charging handle. It should eject the round without difficulty.)
At the range or hunting camp - try this to diagnose the problem.
1. Use a different mag than the one that is not seating or a hard time seating. Load one round into the magazine, then insert to magwell. Chamber the round and fire at safe target. Does it eject the brass? Yes - then its not the extractor. No, then you have to see either a gas problem or extractor problem. Does it lock the bolt to the rear? Yes - no gas problem. No - then gas or cycling problem.
2. Using the same mag, load two rounds and insert into magwell. Chamber first round and fire at safe target. Does it eject the brass? Does it chamber the next round? If yes to both then it could be the magazine that was not cycling was the problem. If it shoots, ejects the brass but does not pick up the next round, then you either have a gas problem or something else is preventing the bolt from moving all the way back to pick up the next round.
Good luck.
oneshot
Master
I don't try and fix AR's on the internet. any more But will be glad too look at it If you make a effort to bring it up. Just my 100 cents jj
TackleberryMCS
Master
I have a good question. What ammo?
I tried 14 different gen 3 Pmags both full load and with some rounds taken out, and a few metal mags from a friend that was there. When it would fire it would eject the spent casing and load a new round but it would not fire that new round. I could manually retract the bolt which would eject the unfired round, load another and it would then fire....I have never experienced anything like it.
TackleberryMCS
Master
It sounds like the bolt is not fully seating for some reason. Might I suggest, remove the BCG an break it down and give it a thorough cleaning. Afterwards, liberally lube the bolt and re-insert it into the carrier, then liberally lube the carrier. Also, take a chamber brush to the chamber and clean it to make sure it is free of any residue. Try shooting it again.
Grassflatsfisher
Expert
Sounds like a deep cleaning and lube job is in order. Gas block and tube may need cleaning also. Might be blocked and not allowing enough pressure to force the bolt back far enough to grab the next round.
Marquezj16
Marksman
Yup, clean that chamber really good.
Hey there. This could be a few things. You might just be light striking. Break down your bolt completely and remove the pin from the extractor and clean that with a quality cleaning agent. Remove the firing pin, and clean the firing pin channel with some cleaning agent. Or you can take out your entire carrier and leave it in COLEMAN fire oil for a couple hours, and proceed to clean it. I had an issue with light striking due my firing pin channel being very dirty, the pin was getting hung up on gunk. So it might be a simple fix...or your bolt might be no good. A good way to to check if your BCG is still good, is to pull the bolt carrier group out of the rifle, and extend the bolt, and sit it horizontally on the table. If the bolt collapses on itself. The bolt needs to be replaced. If the bolt is loosely fitting the carrier due to being "over worked" our "out shot" light striking can occur, as well as extraction issues. When I wear out a bolt, I typically can fire off a round or two, and then some won't be struck by my firing pin at all. Also, inspect your pin for damage. The best way to see if this is a bolt carrier group issue, is to have another on standby.
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John B.
Master
Break that bolt down... definitely something that gets overlooked a lot of times... 2 Allen screws and a cotter pin, you'll be surprised how filthy it is in the cracks and crevices.
Blackeyes
Expert
Yup, sounds like a bolt issue, Pmags of any sort run like butter in my MP (and everything else I have)
Clean that thing up good, lube it and retry
Clean that thing up good, lube it and retry
