Hey guys i have a M&P 40 that ive been trying to solve this problem for a while now currently the gun has
Trijicon NightSights,
Apex Duty Carry Trigger kit,
Apex AEK Trigger,
Apex RAM,
Apex Failure Resistant Extractor,
However when it started it only had the sights and the Carry Duty Trigger kit installed, probably about 2000 Rounds into it it starting sort of ripping the brass upon ejection, (ill leave pictures below),
first i stripped the whole gun down cleaned it re assembled it with no luck,
I tried replacing the Recoil spring guide rod assembly, no luck
next i replaced the extractor still no luck, its beginning to bug me, i would like to try and not send it in and be without my gun for weeks any input would be greatly appreciated!
the FTE jam in the picture is a actual jam while at the range today also!

Looks like it is short cycling. Have you tried different ammo?

NOT from personal experience but I've heard if you need to send a firearm back to S&W for warranty repairs & you have Apex or other after market parts installed they'll remove them & replace them with factory original parts & charge you for parts & labor. They won't send the parts back to you. You'd be okay with the Trijicons, though. They sell M&Ps with them installed. You'd probably be better off finding a good gunsmith in your area. S&W will blame anything wrong with your pistol on the after market parts. I've heard of this happening to several people. You could reinstall everything you changed but that won't determine if those were the cause. Until my 40C has been well used & not just a half year old with only about 500 rounds through it I'll be leaving it stock for now. My FS 40 is also stock & that's 4 years old.

I hope you can resolve your problem.

__________________
Former USN, Retired US Army

it is none of the aftermarket parts returned the gun to stock and still does it, also yes i have tried multiple types of ammo including higher end match grade to cheap dirty ammo, even reloads. they all do the same thing with the aftermarket parts installed and without them.

It definitely looks like it's short cycling. The most common cause for this is installing a recoil spring that is too strong for the cartridge energy level. If you are using factory ammo I would suggest that you order a bone stock original replacement recoil spring for your M&P. Because I have a sneeking hunch that you may have the recoil spring for the 45 ACP M&P in your 40 caliber M&P.

Second most common cause for this is an issue with the shooter not supporting the handgun firmly enough. Or in other words "limp wristing" the pistol.

I agree with scooter on the recoil spring. If the wrong one is installed things will not work right.

Take a look at the ejector and extractor as well.

Just a question, did you buy the gun new? Or did the changes you describe come with the gun when you got it?

tipoc

I bought the Pistol new and had everything done to it, it randomly started doing it after about 2000 rounds with the original recoil spring, as i stated in the post i Replaced the recoil spring with a factory replacement. Still did the same thing, and recently i just put the APEX failure resistant extractor in it and a brand new factory replacement ejector also, and i am not limp wristing the gun, It does it no matter who shoots it

I'll try to help a bit.

This problem from the pics looks like what many shooters call a double feed malfunction. It really isn't exactly that but let's eliminate things. The brass is being caught by the slide and banged up. This is a problem of ejection and extraction but a few things could cause it.

I'll assume that this is factory ammo and not reloads.

I'll also assume that this happens with all the mags that you have. If it occurs with only one magazine but works well with the others then we'd know what the problem is.

Next let's rule out user induced malfunctions. Make sure that you aren't inadvertently doing something to slow down the slide, rubbing it with your hand or activating the slide release.

If the Apex trigger was properly installed that will not have anything to do with this problem.



Look at the chamber. If it's rough or oversize that could cause the problem, but if so it likely would have shown up right away.

Are you sure the recoil spring is the proper one? See as the slide moves backward after the round fires, the extractor grabs the rim of the case and pulls it from the chamber. It pulls it rearward till it hits the ejector which flips the round upward and out of the ejection port as the slide reaches it rearmost position. If the magazine is functioning properly, a new round rises and as the slide moves forward hits that and pushes that into the chamber. There are three points here that could cause the problem that you are having. Slow or faulty extraction of the case, the mag is releasing the round too soon and it pushes the extracting round out of place, or the ejectior is the wrong one or damaged.

These are the things you need to look at.

From what you say it's hard to tell when this problem began, if you began changing things to try to solve it or if one of the changes created it. You'll most likely know these things.

Was it you who did the work on the gun (parts changes) or someone else?

Hope this helps some.

tipoc

Is the ejector installed in the sear housing block?

If someone has removed the sear housing block (or the sear pin & sear), it's not difficult to forget to put the ejector back where it belongs.

Just a thought.

__________________
Ret LE Firearms inst & armorer

Ejector can also be tuned by changing its angle a tad.. in your case a little off the top with cause the spent round to flip up and out faster. Also a miss fit or very tight extractor will cause the same issues. Check the fitment.. This can be done with the slide off the frame and fit a round by hand under the extractor. it should not be a tight fit in fact lose is better.. But this will give a idea on where your issue is.. Your local gun shop or friendly gunsmith should have it under control in less than 5mins and may not even charge you.. It's realy a easy fix. George

this all started with about 2000 rounds on the gun and with ALL factory components except for the Apex trigger kit and nightsights those were the only mods to the gun. The ejector and extractor are brand new the recoil spring assembly also brand new, all ordered from brownells
below ill link recoil spring,ejector and extractor i installed in the gun

Recoil Guide Rod Assembly : RECOIL GUIDE ROD ASSEMBLY | Brownells

Ejector : EJECTOR | Brownells

Failure Resistant Extractor : S&W M&P FAILURE RESISTANT EXTRACTOR | Brownells

Like i said though it was doing the SAME thing with the factory parts also

So (according to you) you've eliminated the pistol from the equation, what does that leave? In my mind it's ammunition or the shooter. If you still think it's something in the pistol, instead of trying random suggestions on the internet where nobody can actually inspect the pistol, maybe it's time to send it to S&W or a qualified gunsmith.

__________________
Minimize the variables

ive tried multiple types or ammo had multiple people shoot the gun with the same results, not the ammo or the shooter

Then it may be best to have an actual pistolsmith look at the gun or return it to S&W with an explanation.

The gun began to malfunction. You've tried to repair it by changing out parts which you have installed yourself. The problem has persisted and possibly gotten worse. It does it with various brands of ammo and all the mags that you have (that last part is correct isn't it? I don't see where you mentioned trying different magazines). You have examined th piece carefully and don't see the source of the problem.

At this point it's difficult to diagnose this from long distance without seeing the gun. If you live close to a forum member maybe they can handle and look at the gun as a favor. But other than that it may be time for a gunsmith or S&W. No point in spending more money on random parts.

tipoc

Let me also suggest that you go to the Ammunition-Smithing section of this forum for more specialized information on this issue. It may have come up before post a link to this thread there.

http://smith-wessonforum.com/s-w-smithing/

tipoc