The S&W M&P problem thread

[orionz06]

Would you mind posting exactly what tools you need to put the parts in yourself. I want to order this kit for mine, but I want to make sure I have everything necessary to install it beforehand. Thanks.

I used a 1/16" punch and a wood block with a hole in it to support the frame and retain the pins. The best thing going now is the slave pin Apex includes for the trigger spring, put that in there and it should go together like a breeze.

[SteveL]

I used a 1/16" punch and a wood block with a hole in it to support the frame and retain the pins. The best thing going now is the slave pin Apex includes for the trigger spring, put that in there and it should go together like a breeze.

Thanks for the response. I don't think I'll have too much trouble.

[orionz06]

It is quite simple, just pay attention and orient the loop of the spring correctly. The armorers manual states this for certain, I believe Apex shows this on their website as well.

[SteveL]

It is quite simple, just pay attention and orient the loop of the spring correctly. The armorers manual states this for certain, I believe Apex shows this on their website as well.

Will do. Thanks again.

[crazymoose]

Couldn't find this posted yet in this thread: failure of the barrel just forward of the hood.

Not my experience, but this guy seems to have documented the circumstances of the failure pretty thoroughly.

http://www.youtube.com/watch?v=-yOcP...os=NgXRSzrb6q0

Note that this failure does not seem to be endemic to the M&P line at all. In fact, I don't know that I've ever seen another such failure either in person or with photo documentation. I'm not a metallurgist or a mechanical engineer, so I'm really just speculating out of my ass here, but my theory is this: maybe the close to 90º angle where the barrel meets the hood area is a stress point from which fractures can propagate. Just stripped a Glock for comparison's sake, and the Glock has a relatively gently radiused area where the barrel meets the hood. I've seen that Beretta and Springfield (with the XD) radiused the corners on their locking blocks, because this was a frequent failure point and site of cracking. I wonder if the same principle is at work here. Any engineers care to either back me up or shoot me down if I'm wrong?

In any event, since this is not a common failure, it can't only be the design geometry. I wonder if he got an improperly heat-treated barrel or something.

[RogerinTPA]

While at the range this afternoon, I loaded a mag, released the slide vis the slide lever (as usual), went to pull the trigger and nothing. The trigger moved the entire slide, but would not break or fire. This happened twice. I cleared the weapon, then attempted to dry fire, it worked. I went on to shoot as normal. Around the 8th mag, it happened again. I performed the same method as above, then continued shooting as normal. I shot 7 more mags through her with no other issues. Is there a hang up with sear or trigger bar since the slide did move as a pressed the trigger? Why would it continue to function? FYI, the weapon has 9, 500 rounds on her. Around 3000 after installing the Apex sear. Any thoughts on what I should inspect or tweak?

[VirginiaTactical]

While at the range this afternoon, I loaded a mag, released the slide vis the slide lever (as usual), went to pull the trigger and nothing. The trigger moved the entire slide, but would not break or fire. This happened twice. I cleared the weapon, then attempted to dry fire, it worked. I went on to shoot as normal. Around the 8th mag, it happened again. I performed the same method as above, then continued shooting as normal. I shot 7 more mags through her with no other issues. Is there a hang up with sear or trigger bar since the slide did move as a pressed the trigger? Why would it continue to function? FYI, the weapon has 9, 500 rounds on her. Around 3000 after installing the Apex sear. Any thoughts on what I should inspect or tweak?

I have actually seen this happen a few times on my M&Ps, particularly my wife's. She had around 10k on her 9mm and the same would happen. I replaced the recoil guide rod assembly, and it fixed the problem. Have you replaced your recoil guide rod assembly at all? S&W recommends you replace it every 5,000 rounds according to the maintenance guide. If you have a weak spring, it is not allowing the slide to go into battery the whole way. If it is because the slide is not in battery the whole way, I would recommend replacing the recoil guide rod assembly. Once you press the trigger, the striker being released would push the slide forward, but since the slide was not all the way forward it may or may not engage the striker safety plunger. In that case, the trigger would release the striker, but the safety plunger would be doing its duty since the trigger bar did not activate it.

[ralph]

Couldn't find this posted yet in this thread: failure of the barrel just forward of the hood.

Not my experience, but this guy seems to have documented the circumstances of the failure pretty thoroughly.

http://www.youtube.com/watch?v=-yOcP...os=NgXRSzrb6q0

Note that this failure does not seem to be endemic to the M&P line at all. In fact, I don't know that I've ever seen another such failure either in person or with photo documentation. I'm not a metallurgist or a mechanical engineer, so I'm really just speculating out of my ass here, but my theory is this: maybe the close to 90º angle where the barrel meets the hood area is a stress point from which fractures can propagate. Just stripped a Glock for comparison's sake, and the Glock has a relatively gently radiused area where the barrel meets the hood. I've seen that Beretta and Springfield (with the XD) radiused the corners on their locking blocks, because this was a frequent failure point and site of cracking. I wonder if the same principle is at work here. Any engineers care to either back me up or shoot me down if I'm wrong?

In any event, since this is not a common failure, it can't only be the design geometry. I wonder if he got an improperly heat-treated barrel or something.

I suppose that is possible, I remember a few years back when Springfield Armory, had a rash of problems with their longslide 1911's, the front of the slide would break off during firing, and this actually happened to a few people, as it was all over the 'net..Turns out, a batch of slides were overcarburized..basically making them brittle, someone screwed up the heat treat..Anyway, SA did fix all of them..These things do happen, it's rare, still, it happens..

[RogerinTPA]

I have actually seen this happen a few times on my M&Ps, particularly my wife's. She had around 10k on her 9mm and the same would happen. I replaced the recoil guide rod assembly, and it fixed the problem. Have you replaced your recoil guide rod assembly at all? S&W recommends you replace it every 5,000 rounds according to the maintenance guide. If you have a weak spring, it is not allowing the slide to go into battery the whole way. If it is because the slide is not in battery the whole way, I would recommend replacing the recoil guide rod assembly. Once you press the trigger, the striker being released would push the slide forward, but since the slide was not all the way forward it may or may not engage the striker safety plunger. In that case, the trigger would release the striker, but the safety plunger would be doing its duty since the trigger bar did not activate it.

Good info to know. No, I haven't replaced the recoil guide rod assemblies. I'll have to order a few since I'm quickly approaching or have exceeded the 9K mark on 3 of my M&Ps.

[Ed L.]

Well, I got a new problem with my M&P9. It seemded that every 1200-1500 rounds the gun would fail to detonate a round. I had this happen with several brands of ammo so I wrote it off to a freak occurrance.

I probably have over 7,000 rounds through the gun, so I replaced the recoil spring assembly. I was using some Barnual Brass ammo which I have used before, but this time I experienced at least 1 failure to detonate per 50 rounds. In one case I put the round back in and it detonated without issue. I have used Barnual before without issue. Perhaps it is this particular batch of Barnual that has harder primers. However, I was also shooting a Gen 2 Glock 17 using the same ammo and had no issues with the gun.

Needles to say, I find this issue very troubling.