UPDATED: resolved- odd M&P malfunction tonight at the match

[BaronFitz]

I was shooting my M&P 9 Pro tonight at the KSTG match at the NRA, and had a bizarre malfunction that made me question my grip on reality. Unfortunately, it was right at the start of the stage, so calling a time out and taking a picture with my phone was out of the question. I reduced it and drove on, but it messed up my concentration for the rest of the stage.

Description:

After finishing the previous stage, I had a round in the chamber, and was instructed by the RO to remove the partial mag, and top off with a full one, leaving me with 11 rounds in the gun total.

Starting the stage in question, I drew, pressed out, and found a dead trigger. It felt like it hadn't reset from the last stage, rather than a bad strike. I did the tap-rack, completed the stage, and retrieved the round I had ejected. It had no dimple on the primer, and I fired it successfully later.

So my question is: what happened here? Is it possible that the striker followed the slide forward on the last round?

The gun has an Apex kit in it (not sure if the duty or competition model, since it was in it when I bought it used), and the Apex RAM. I seem to recall something similar happening once before in a RB1 course, but it was in the middle of an extended string of fire, and I had to reduce and drive on.

[High Altitude]

Sounds like sear bounce.

Does your pistol have the small sear spring or the updated large sear spring?

I was shooting my M&P 9 Pro tonight at the KSTG match at the NRA, and had a bizarre malfunction that made me question my grip on reality. Unfortunately, it was right at the start of the stage, so calling a time out and taking a picture with my phone was out of the question. I reduced it and drove on, but it messed up my concentration for the rest of the stage.

Description:

After finishing the previous stage, I had a round in the chamber, and was instructed by the RO to remove the partial mag, and top off with a full one, leaving me with 11 rounds in the gun total.

Starting the stage in question, I drew, pressed out, and found a dead trigger. It felt like it hadn't reset from the last stage, rather than a bad strike. I did the tap-rack, completed the stage, and retrieved the round I had ejected. It had no dimple on the primer, and I fired it successfully later.

So my question is: what happened here? Is it possible that the striker followed the slide forward on the last round?

The gun has an Apex kit in it (not sure if the duty or competition model, since it was in it when I bought it used), and the Apex RAM. I seem to recall something similar happening once before in a RB1 course, but it was in the middle of an extended string of fire, and I had to reduce and drive on.

[BaronFitz]

No clue. How do I find out, short of taking it to an armorer?

[beastfrog]

Sounds like a dead trigger.If you have the small sear plunger/spring get the large one. If you have the large sear plunger/spring clean it. Might be worth checking the striker but since it worked later it's prob fine.

Fun match.

[High Altitude]

No clue. How do I find out, short of taking it to an armorer?

Only way to find out is to remove the sear housing and look.

If you have the small spring and want to update it, you either have to purchase a new sear housing and swap it in, send your housing to Apex and have them mill it to accept the larger spring/plunger or you could call S&W, explain your issue and most likely they would update the pistol if it needs it.

[High Altitude]

If you want to see what is involved in detail stripping the pistol yourself, look up Apex's vids on youtube.

It isn't that hard to do and you do not have to remove the trigger end of the gun to get the housing out.

[JHC]

That fail to reset "dead trigger" while not exactly common did occur in a number of M&Ps for some years although it's been reported on this forum that S&W resolved this with some changes rolled into production last year or so.

[BaronFitz]

Thanks for pointing out the term "sear bounce". Now I know what to search for. I'd bet money that the too small sear spring is the issue, since it's a gun of unknown age (I bought it used). I already had to swap the extractor for a better one due to FTEs. Looks like I'm taking it out of my carry lineup until this is fixed. I'd hate to have a dead trigger when it's go time for real.

I'll try to post back here once it's fixed with what I did to fix it.

[ruchik]

If you find a small sear spring and plunger and would like to upgrade to the current, larger spring and plunger, this is what you need. I bought and installed that part myself. Very straightforward stuff, has all the parts you need in it including the sear itself in it. Just lift out the entire old block, and drop in the entire new block.

It is worth noting that the new block listed above has the magazine safety and internal lock in it. Both can be removed in about 10 mins using these links here and here.

[C4IGrant]

I was shooting my M&P 9 Pro tonight at the KSTG match at the NRA, and had a bizarre malfunction that made me question my grip on reality. Unfortunately, it was right at the start of the stage, so calling a time out and taking a picture with my phone was out of the question. I reduced it and drove on, but it messed up my concentration for the rest of the stage.

Description:

After finishing the previous stage, I had a round in the chamber, and was instructed by the RO to remove the partial mag, and top off with a full one, leaving me with 11 rounds in the gun total.

Starting the stage in question, I drew, pressed out, and found a dead trigger. It felt like it hadn't reset from the last stage, rather than a bad strike. I did the tap-rack, completed the stage, and retrieved the round I had ejected. It had no dimple on the primer, and I fired it successfully later.

So my question is: what happened here? Is it possible that the striker followed the slide forward on the last round?

The gun has an Apex kit in it (not sure if the duty or competition model, since it was in it when I bought it used), and the Apex RAM. I seem to recall something similar happening once before in a RB1 course, but it was in the middle of an extended string of fire, and I had to reduce and drive on.

What size is the sear plunger in your gun? Tiny one or the big one?

If you have an M&P made prior to say June 2011, you have the small sear plunger. This is the issue. You can just call up S&W CS and tell them that you have a dead trigger. They know all about it and will issue you a call tag.



C4