Smith Wesson M&P Striker Block Potential Issue with Apex kits.

[SSW]

Disclaimer I am not a gunsmith, make no claim of any specific issue or statement that any part is problematic. Just passing on an observation of a possible safety issue that seemed to surprise many people with much more knowledge than me. Being a safety question thought sharing the observation was responsible and if you feel your firearm may have this issue or you have questions, please contact a gunsmith.

My SW M&P was safety checked recently. My firearm has an Apex kit installed had issues with the striker block safety not engaging.

The striker block was working after I installed the Apex kits, so the consensus seemed to indicate that one or more components of the M&P or Apex kit seemed to wear out.

The test in the manual for this is simple. With the firearm unloaded, magazine removed, muzzle in a safe direction, move the slide into slide lock. Then remove the slide or turn the firearm over and press against the exposed tab behind the striker. There should be no forward movement. If it moves forward freely the striker block is not working and the striker may need to be replaced. (paraphrased)

With a new striker installed the firearm was rechecked and all was fine.

So again no specific claims being made here. Just passing this on as there may be a potential that with the striker block not working the gun may discharge if dropped.

I searched this topic and didn't find it so I figured I would pass on my experience. YMMV IANAGS


Safe shooting,
Scott

 

[taz-2005]

I've noticed that after putting the kit in a new gun. I'm not a gun smith either, but from what I've observed the way they were testing is not entirely accurate. If you pull the tab on the striker back the SB should engage. The "slack" gets taken up by the movement of the slide going into battery thereby engaging the striker block that way.

 

[SJan]

The test for this is simple. With the firearm unloaded, magazine removed, muzzle in a safe direction, move the slide into slide lock. Then turn the firearm over and press against the exposed tab behind the striker. There should be no forward movement. If it moves forward freely the striker block is not working and the striker may need to be replaced.

How much movement was there on your firearm?
Did it wiggle a bit fore and aft, or move fully forward until the striker was protruding from the breech face?

- - - Updated - - -

I've noticed that after putting the kit in a new gun. I'm not a gun smith either, but from what I've observed the way they were testing is not entirely accurate. If you pull the tab on the striker back the SB should engage. The "slack" gets taken up by the movement of the slide going into battery thereby engaging the striker block that way.

That is true, the striker on the M&P is not cocked until the slide is fully forward.

 

[eisenhow]

Where is the test procedure documented? I'm not familiar with the official safety test procedures on striker fired guns.

It sounds like they don't start the test with the stiker reset. If they racked the slide and then locked it back the striker would be stop by the striker block. How filthy was the striker and the striker channel?

 

[SSW]

All legit questions. In my case the movement was fully forward, with the "old" striker, once replaced there was very little movement. The SB was reset before attempting to move it forward. The gun was racked as part of the safety check process.

I am far from an expert, but at least one gunsmith had the same type of issue and showed me how to fix mine. So while my description may be lacking technical detail, it really did seem to be a legit concern.

My description is probably not the best. That's my bad.

 

[noxin]

Did you replace the striker block or the striker w/firing pin to resolve it?

 

[SSW]

Did you replace the striker block or the striker w/firing pin to resolve it?

The striker with the firing pin.

 

[noxin]

okay, thanks for the info!

Have you emailed Apex about it?

 

[eisenhow]

Which APEX kit was it: Duty/Carry AEK, competition AEK, or FSS?

If the USB was binding or the USB spring was took weak (competition?) it could cause this test to fail. However, based on your description of the fix (replace the striker) I can only assume it was a competition AEK and a weak striker spring.

 

[SSW]

I haven't emailed Apex, I am not sure it is an issue with their parts or not, but that may be a good idea.

In my gun the Apex kits installed were the DCAEK and RAM. I didn't install the competition kit.

 

[FSTC]

Apex was emailed.

All of the guns affected had the USB installed

All guns were corrected with the installation of a new striker.

And Mike, the procedure used was adapted from the manual. (the adaptation was the slide was still on the pistol. the striker function test is the same on and off the gun)
The striker bypassed the block with NO noticeable movement in the in the USB.

FWD to 5:00 to see the Apex function check, Again, on or off the gun the results are the same.

 

[FSTC]

but from what I've observed the way they were testing is not entirely accurate. If you pull the tab on the striker back the SB should engage.

Please explain what was "not entirely accurate" about the test procedure? I am assuming you were there?

So what happens when you push the tab?

 

[eisenhow]

Dan thanks for the details. I'm going to go check my 4 M&P's today. Were the strikers worn or rounded off where they engage the USB?

 

[Glockster30]

Just another good reason for buying an ugly Glock!

 

[eisenhow]

Dan thanks for the details. I'm going to go check my 4 M&P's today. Were the strikers worn or rounded off where they engage the USB?

OK, I checked 3 of my M&P's and here are the results:

M&P full size (NO apex parts, Larocca trigger): No problems, the striker resets itself every time and striker block blocks

M&P40Pro (APEX FSS kit): No problems, the striker resets itself every time and striker block blocks

M&P9L (APEX competition kit):

• This gun has the most rounds through it.
• striker is blocked every time IF the striker is reset.
• There is some slight movement (more than the other two) of the striker but the USB blocks the striker well before the it's anywhere near the breach face.
• If you push the striker block down and push the striker forward you can find ways to have the striker NOT reset (it gets bound if you push it slightly to the side
• I removed and cleaned the striker and striker channel and I can still get it to happen
• If you racked the slide and start with the striker reset the striker block always functions

So the open question: Is this a real safety issue? In operation is there any case where the striker won't be reset by the action of the gun and a live round is in the chamber? I'm interested to hear what APEX response is.

 

[Almostelmo]

I checked my M&P9 with Comp AEK (~1k shots fired) and my Shield 9 with DCAEK (~500 shots fired) and both functioned as intended. I'll keep an eye on this though.

 

[taz-2005]

Please explain what was "not entirely accurate" about the test procedure? I am assuming you were there?

So what happens when you push the tab?

M&P9L (APEX competition kit):

• This gun has the most rounds through it.
• striker is blocked every time IF the striker is reset.
• There is some slight movement (more than the other two) of the striker but the USB blocks the striker well before the it's anywhere near the breach face.
• If you push the striker block down and push the striker forward you can find ways to have the striker NOT reset (it gets bound if you push it slightly to the side
• I removed and cleaned the striker and striker channel and I can still get it to happen
• If you racked the slide and start with the striker reset the striker block always functions

So the open question: Is this a real safety issue? In operation is there any case where the striker won't be reset by the action of the gun and a live round is in the chamber? I'm interested to hear what APEX response is.

Eisenhow's response expands on what I was trying to say. I don't think it's a real issue, but would like to hear what APEX says as well.

 

[eisenhow]

View attachment 83662

Based on the S&W armorer manual "Pull the striker to the full rear position" my 9L would have passed the test as written.

I think the striker should reset on its own, I will replace mine or find out what's causing it and fix it. However, this is why it is very important that a documented procedure is used for tests like this. I know there was a lot of discussion about glock trigger checks at A7 this year. I think it would be a good idea for any sport (IDPA, USPSA, etc, I'm not singling any one sport out) to document how these tests should be done.

 

[SJan]

I checked my 2 M&Ps.

#1 has several thousand rounds total, most with a DCAEK/RAM, but recently changed to the Apex FSS/aluminum trigger kit.

#2 is still quite new, 500-1000 rounds, has the the DCAEK/RAM (from #1)

Both passed. The higher millage gun has more wiggle to the striker.

It seems like a whole lot of wear would have to be present on the striker and/or striker block for it to fail the described test. I think if the striker block spring were broken might be a more likely reason for a test fail.

 

[FSTC]

So the open question: Is this a real safety issue? In operation is there any case where the striker won't be reset by the action of the gun and a live round is in the chamber? I'm interested to hear what APEX response is.

The issue lies with the striker not being caught by the block and entering the breech causing a discharge. The SB is a "drop safety" if a loaded pistol was dropped, the inertia could cause the striker to contact the primer resulting in discharge.
For this scenario to happen the striker would have to "jump" the sear as well.

 

[FSTC]

It seems like a whole lot of wear would have to be present on the striker and/or striker block for it to fail the described test. I think if the striker block spring were broken might be a more likely reason for a test fail.

The affected pistols had the USB installed. The springs "felt" intact. Also no movement of the USB (Indicating missing or "weak" springs) My initial thought was, weak spring.
I also did not notice any difference in the striker assembly. However the USB functioned correctly with a new striker installed.

 

[eisenhow]

The affected pistols had the USB installed. The springs "felt" intact. Also no movement of the USB (Indicating missing or "weak" springs) My initial thought was, weak spring.
I also did not notice any difference in the striker assembly. However the USB functioned correctly with a new striker installed.

Was the striker pulled all the way back (per the S&W armorers manual) or was it after it was moved forward? I see 3 possible things:

1. The USB was bound and/or the USB spring was too weak to reset it. That way you would see no visible movement of the USB as you moved the striker forward. Replacing the striker wouldn't fix this so I rule this out.
2. The striker was worn or damaged and a properly reset USB allows it to pass
3. The striker was not actually reset, therefore the USB didn't reset. The striker would appear to move past the USB. However the striker was not reset per the armorers manual.

Based on what I observed with my gun I'm guessing it is number 3. It could be number 2, there were have to be some noticeable differences between the old and new striker for this to happen.

 

[SSW]

Glad to see people are talking about this and checking their M&Ps. In my OP I said this is a potential issue.

Eisenhow, my situation appears to be #2 on your list.

I just reinserted my old striker. Specifically assure the striker was reset and without any wiggling or depression on the tab, it traveled fully forward with just slight pressure in a forward direction. Put new striker back in and all issues resolved.

So based on my non-scientific test at least in my gun the only part changed in any way was the striker. And replacing it fixed the issue.

I know others including a gunsmith had the same or similar situation with the same solution, replacing the striker. YMMV IANAGS

My hope was to bring awareness not accuse SW or Apex in any way. I am far from having the credentials to do that. Just glad people are talking about and checking their guns!!! Even if the chance of something going wrong is remote, given the number of M&Ps out there someone will be that 1% and I don't want that to be anyone!!

 

[KH56010]

This has been a known problem for a while, so far only confirmed with the APEX kits. I found out when my gun doubled shooting at a texas star during the spring. Pulled out the striker and found that the striker leg was completely peened over which allowed it to smoothy go right on past the USB.

Obviously, that wouldn't cause the double, I have the FSS trigger in both of my guns and I'm sure messing with the trigger loop and all the fine tuning along with the low height of the apex sear had something to do with it. I believe I have remedied what caused the double, but I do still have an issue with peening the striker legs. To the point where I have to buy a new striker every couple of months.

I talked to APEX about this, they said they had a redesigned USB and sent that to me, didn't fix the problem. I haven't had enough rounds through my stock M&P to find out if it happens on those as well. If it does then I imagine this happens just from the striker bouncing around and off of the USB during recoil. I also use competition striker springs in both my FSS equipped guns, so that may have an effect on the bouncing around too.

 

[taz-2005]

This has been a known problem for a while, so far only confirmed with the APEX kits. I found out when my gun doubled shooting at a texas star during the spring. Pulled out the striker and found that the striker leg was completely peened over which allowed it to smoothy go right on past the USB.

Obviously, that wouldn't cause the double, I have the FSS trigger in both of my guns and I'm sure messing with the trigger loop and all the fine tuning along with the low height of the apex sear had something to do with it. I believe I have remedied what caused the double, but I do still have an issue with peening the striker legs. To the point where I have to buy a new striker every couple of months.

I talked to APEX about this, they said they had a redesigned USB and sent that to me, didn't fix the problem. I haven't had enough rounds through my stock M&P to find out if it happens on those as well. If it does then I imagine this happens just from the striker bouncing around and off of the USB during recoil. I also use competition striker springs in both my FSS equipped guns, so that may have an effect on the bouncing around too.

Do you think this has do the design changes on the M&P? I wonder if the newer version does not have an issue but the older design does perhaps? I ask because on my guns I never had to adjust the trigger bar loop and they have the tear drop cut.

 

[eisenhow]

Eisenhow, my situation appears to be #2 on your list.

I just reinserted my old striker. Specifically assure the striker was reset and without any wiggling or depression on the tab, it traveled fully forward with just slight pressure in a forward direction. Put new striker back in and all issues resolved.

It would be interesting to see some pics of what both strikers looked like.

This has been a known problem for a while, so far only confirmed with the APEX kits. I found out when my gun doubled shooting at a texas star during the spring. Pulled out the striker and found that the striker leg was completely peened over which allowed it to smoothy go right on past the USB.

Obviously, that wouldn't cause the double, I have the FSS trigger in both of my guns and I'm sure messing with the trigger loop and all the fine tuning along with the low height of the apex sear had something to do with it. I believe I have remedied what caused the double, but I do still have an issue with peening the striker legs. To the point where I have to buy a new striker every couple of months.

I talked to APEX about this, they said they had a redesigned USB and sent that to me, didn't fix the problem. I haven't had enough rounds through my stock M&P to find out if it happens on those as well. If it does then I imagine this happens just from the striker bouncing around and off of the USB during recoil. I also use competition striker springs in both my FSS equipped guns, so that may have an effect on the bouncing around too.

Very interesting. This is the first I've heard of it. I'm surprised that I haven't read about this before over on Brian Enos Forum There has got to be a ton of M&P's with these parts in them. I wonder if Flork would chime in but it doesn't look like he has logged in a year and a half.

 

[KH56010]

Do you think this has do the design changes on the M&P? I wonder if the newer version does not have an issue but the older design does perhaps? I ask because on my guns I never had to adjust the trigger bar loop and they have the tear drop cut.

I have old and new M&P's, messing with the trigger bar loop is only an FSS thing. You have to adjust it (not for all, but most M&P's) because there is such little trigger to pull, that it won't always drop the sear. I have since cut off the trigger safety on the FSS trigger and taken a ton of metal out in my attempt to hunt down what was causing the striker leg to peen. I have it set now so that the USB is twice as far up in the channel once the striker is released, I may even have taken a video of it and put that on my computer somewhere. There's not a chance in hell my striker contacts the USB when the gun goes bang, so I'm really thinking that it's from the striker bouncing around under recoil. But, you don't really notice the peening for at least 1000 rounds and my stock M&P (AKA, carry M&P) has far fewer than that through it.

 

[KH56010]

Ahh, looks like I had it on my youtube page for when this thread was happening on Benos.com

http://www.youtube.com/watch?v=uGu1qSAxKwM

So the first gun (top one) is with the FSS and trigger loop modified so that the USB was nearly all the way pushed up before the striker releases. It's actually up higher than even a stock gun would have it at.

The second gun (bottom) is what the USB looks like with a stock FSS installed.

Pulled both triggers all the way until just before breaking point to show how far up the USB's were, and then released the sears. Both guns still peen the striker...

 

[KH56010]

It would be interesting to see some pics of what both strikers looked like.


Very interesting. This is the first I've heard of it. I'm surprised that I haven't read about this before over on Brian Enos Forum There has got to be a ton of M&P's with these parts in them. I wonder if Flork would chime in but it doesn't look like he has logged in a year and a half.

It's becuase the M&P sub thread has gotten too damn busy! Here it is, buried down from May: http://www.brianenos.com/forums/index.php?showtopic=172016

 

[eisenhow]

It's becuase the M&P sub thread has gotten too damn busy! Here it is, buried down from May: http://www.brianenos.com/forums/index.php?showtopic=172016

Now that you mention it I recall seeing the thread. I think I even went and functioned checked my 40Pro with a FSS. I didn't pull and check the striker. Now I've got to go check all my strikers and compare them to one of my spare new ones.

Based on that thread I'm really disappointed in APEX response. They replaced parts on an individual basis. However, they didn't respond to the thread or make any statements on the subject. With all the e-mail's they send out you'd think they say "go recheck your USB function and contact us if you have a problem".