M&P 40 v1.0 Striker block not catching striker

[jawman]

I was cleaning my full size v1.0 M&P 40, and when doing a function check before putting it back together, I noticed that I could push the striker forward with my finger and the firing pin would protrude through the hole. It seems as if the striker block wasn't fully catching the striker. I think the spring of the striker is not fully resetting, thus not catching on the striker block. Once I forced the striker back to its full resting position, it is caught by the stiker block and it does block me from pushing the striker forward, as intended. However, if I press the striker block down, push the striker forward, it doesn't always fully reset, and thus I can keep pushing the firing pin through. This is concerning because I believe that means the gun is no longer drop safe.

Below is a video showing what I am talking about. Watch both the striker, firing pin, and striker block. Might have to watch it a few times and focus on the different areas each time. You can see that the striker block moves as I'm pushing the striker forward. Should I be calling S&W and have the gun sent to them? Obvious answer is probably: Yes.

I'm also not sure if this would no longer be an issue once the gun is fully assembled, but I don't know if it's possible to test this and I don't like the risk of potentially having a not fully functioning striker block.

[ame]https://www.youtube.com/watch?v=s5fb4wfvAq0&f[/ame]

 

[WR Moore]

Have you replaced your rear sight or removed your striker plunger/block? If so, did you make sure you didn't bugger up the striker plunger/block spring? It's retained by the rear sight.

Not knowing how many rounds you have through the gun, I'd suggest pulling the striker and hosing the plunger down with a spray solvent (carb cleaner/gun cutter etc) and work the plunger up & down until it operates freely. If that doesn't do it, a trip back to S&W is in order.

 

[jawman]

Nope everything is factory. However prior to having this issue, I did remove the striker to clean it as part of my cleaning process, and ran some Q tips in there and Q tipped the striker block. So it's really clean, but it's doing this. I inspected closely and don't see any pieces of Q tip fiber. I don't think a tiny piece of cotton fiber would cause such an issue, but I checked just in case.

 

[CB3]

Edit: My advice below is backwards and wrong. Thanks for others posting correct advice down below about the striker spring. Duh. Mea culpa.



I am not a gunsmith or M&P expert, but what I see in your video is your striker not returning all the way back under striker spring pressure.

When it goes all the way to the rear, the striker block will reset properly. The fact that you can push the striker forward and it stays extended indicates either you left off the striker return spring or the striker channel is obstructed. The striker should return to the rearward position when you let go of the striker tab. Yours does not appear to be doing so.

Remove your striker. Check the striker return spring and make sure the striker channel is clear. While looking in the channel, depress the striker block and see if it clears/blocks the channel correctly. Make sure the striker block moves freely in its channel, and that there is sufficient spring pressure to return the striker block to the fully extended position.

 

[Saudade]

If you pull the striker rearward, like when the slide cycles, does the striker block engage?

 

[Real Old Navy]

Pull your striker and check for any Q-tip fibers or anything else..or any damage. Then watch this vid starting at about 5 mins for reassembly. It looks like the spring on your striker is not fully extending. [ame]https://www.youtube.com/watch?v=6vJQuxBVplY[/ame]

 

[jawman]

If you pull the striker rearward, like when the slide cycles, does the striker block engage?

Yes, it does engage when I pull the striker rearward.

Pull your striker and check for any Q-tip fibers or anything else..or any damage. Then watch this vid starting at about 5 mins for reassembly. It looks like the spring on your striker is not fully extending.

This is actually the same exact video I used to learn how to disassemble and reassemble the striker. I've done everything exactly how it is shown in the video. It's clean as a whistle. No fibers or anything. Completely clean.

 

[Real Old Navy]

Remove the striker AGAIN, examine it, clean it and the hole...something looks like it's preventing that spring from extending.

 

[SoCalDep]

The striker spring is designed to force the striker forward when the striker tail is released as the rear of the sear pivots down.

It will not reset on its own because it is forced rearward as the slide travels forward and the tail catches the sear. The spring naturally wants to keep the striker forward.

Your pistol sounds normal but if you are concerned please don't trust the internet. Have someone knowledgeable check it out.

My M&P Armorer certification is expired now but I have seen a few thousand of them.

 

[Saudade]

Ditto what SoCalDep said. Sounds normal to me. Still inspect for any debris.

Mine do the same thing. If I disassemble it, the striker is restrained by the block. If you push on the block, you'll see the striker slip forward a bit. Any cycling of the slide either by hand or recoil, even just a little bit will catch the striker and pull back enough to engage the block.