Problem with a rifle

[mikec]

I bought a S&W M&P 5.54x39 some years back, and the damned thing has never been reliable. I can clean it as well as I possibly can, breaking the bolt apart, spraying everything, etc, yet it still jams. By jam I mean the bolt locks with a round in it, it will not fire or cycle, and I have to use a rubber mallet to basically hammer the bolt back out. After a good cleaning I got it to run for 90 rounds, but then another time it didn't even run one.

In the past when it does this I have pulled the rear pin, re-cocked the hammer, put the pin back in, and then pulled the trigger again to get the round to discharge. This has worked two times, stopped doing that when the third time I did this the round discharged, but only partially. That time the actual round went into the barrel about 1/2" and unburned powder went everywhere in the action.

This has happened with two types of ammo: Silver Bear, HP zinc plated bi metal casing, and with Barnaul FMJ lacquered steel casing, though not as often with the latter as usually I am at the range where JHP is not allowed.

Any ideas or suggestions? I can't see any visible flaws on any of the pieces, and am just about clueless on what to do next.

Side question: What is bad about using steel casings? How does it hurt the rifle?

[ELVIS]

$150??

god bless.

[Dacotua]

I bought a S&W M&P 5.54x39 some years back, and the damned thing has never been reliable. I can clean it as well as I possibly can, breaking the bolt apart, spraying everything, etc, yet it still jams. By jam I mean the bolt locks with a round in it, it will not fire or cycle, and I have to use a rubber mallet to basically hammer the bolt back out. After a good cleaning I got it to run for 90 rounds, but then another time it didn't even run one.

In the past when it does this I have pulled the rear pin, re-cocked the hammer, put the pin back in, and then pulled the trigger again to get the round to discharge. This has worked two times, stopped doing that when the third time I did this the round discharged, but only partially. That time the actual round went into the barrel about 1/2" and unburned powder went everywhere in the action.

This has happened with two types of ammo: Silver Bear, HP zinc plated bi metal casing, and with Barnaul FMJ lacquered steel casing, though not as often with the latter as usually I am at the range where JHP is not allowed.

Any ideas or suggestions? I can't see any visible flaws on any of the pieces, and am just about clueless on what to do next.

Side question: What is bad about using steel casings? How does it hurt the rifle?

Ive seen this happen on a 6.8

On that gun it had a chamber slightly out of spec and it just wouldnt feed. Reemed the chamber and walla, worked great


Steel ammo- it just makes your chamber dirty. When you fire brass it swells and makes a gasket to your chamber. Almost all the gas goes down the barrel. When you fire steel, the case doesnt expand like brass and it allows some of the gas to go back in your chamber. This will gunk it up in time. Do not fire brass ammo in your gun after shooting steel. You will run the risk of having the brass get stuck. All that carbon that went into the chamber will now stick to the brass and make it stick.

Just clean your chamber if you use steel before you use brass

[ThreeFingerPete]

Dacotua pretty much summed it up. I'd bet that there's either a piece of an old steel case lodged in the chamber (I've seen it happen before) or the chamber is out of spec. The first is a pretty easy solution, the second can be cleared up by a smith in no time.

[mikec]

Dacotua pretty much summed it up. I'd bet that there's either a piece of an old steel case lodged in the chamber (I've seen it happen before) or the chamber is out of spec. The first is a pretty easy solution, the second can be cleared up by a smith in no time.

Thanks Dacotua.


Adam, same rifle you looked at. Did it again afterwards. Think I should ship it back?

[pr1042]

If it's never run right, calling S&W is another option. They have a very good customer service department and most likely would send you a label to ship it in for inspection on their dime

Oh, don't let Elvis lowball you. I'll give you 175 (still waiting to hear back from warranty douches btw)

[ThreeFingerPete]

Thanks Dacotua.


Adam, same rifle you looked at. Did it again afterwards. Think I should ship it back?

I'd call them and explain the problem. They might only want you to send the upper, which would be a lot cheaper.

[Fatass]

I'd call them and get a shipping label.

[bottlerocket]

I bought a S&W M&P 5.54x39 some years back, and the damned thing has never been reliable. I can clean it as well as I possibly can, breaking the bolt apart, spraying everything, etc, yet it still jams. By jam I mean the bolt locks with a round in it, it will not fire or cycle, and I have to use a rubber mallet to basically hammer the bolt back out. After a good cleaning I got it to run for 90 rounds, but then another time it didn't even run one.

In the past when it does this I have pulled the rear pin, re-cocked the hammer, put the pin back in, and then pulled the trigger again to get the round to discharge. This has worked two times, stopped doing that when the third time I did this the round discharged, but only partially. That time the actual round went into the barrel about 1/2" and unburned powder went everywhere in the action.

This has happened with two types of ammo: Silver Bear, HP zinc plated bi metal casing, and with Barnaul FMJ lacquered steel casing, though not as often with the latter as usually I am at the range where JHP is not allowed.

Any ideas or suggestions? I can't see any visible flaws on any of the pieces, and am just about clueless on what to do next.

Side question: What is bad about using steel casings? How does it hurt the rifle?

What is a 5.54x39?

[Brandon-k]

What is a 5.54x39?

Well that's his problem. He's using the wrong ammunition!

[Mach1Run]

What is a 5.54x39?

ak74 round.

http://en.wikipedia.org/wiki/5.45%C3%9739mm

[bottlerocket]

ak74 round.

http://en.wikipedia.org/wiki/5.45%C3%9739mm

Looks like you're thinking of a 5.45x39

[Mach1Run]

I was lol. I totally read that as what he meant to type instead of as he actually typed it.

[IHaveAMustang]

I too have/had issues with my 5.45x39 SBR. I built it myself and it would jam every 10 or 15 rounds (ask BigMuskie, it was jamming on him a lot!)

Turns out it would feed/fire 100% with magpul magazines (but the followers only allow 15 or so rounds in the magazine before it swells and can't be inserted)

The C-Products magazines I bought have really cheap lips and they bend themselves out over time. Once I bent the lips and hammered em down really good, it fed 100% (by hand cycling...)

I haven't gone shooting in about a year, I need to get back out and go to a range...


Edit: Also I had to change my trigger spring out. The stock one wasn't cracking my surplus russian primer. The new uber stiff Wolf spring feels like it could break a 2x4...so try a new trigger spring.