APEX sear, light primer strikes?

MJS

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Hello looking for some help please

I have an M&P Shield in 9mm that I got about 4-5 years ago, one of the first ones out, it has about 2500 rounds through it of factory ammo and 124 grain reloads. I thought I would try the APEX sear after reading all the positive comments from people so I ordered one and I installed it a few weeks ago and at first everything was fine but now I seem to be getting light primer strikes at least one out of every magazine. I was also using an 8 round mag with the +2 mag guts, it was the only mag I had with me otherwise I would have tried a different mag. I clean after every range visit (about 100 or so rounds) and lube with Slide Glide (light) I have always used the light weight Slide Glide with no issues. So my question is what could be causing the light primer strikes? Could it be the APEX sear? Or the Magazine with the +2 MaGuts? This week my plan is to take a factory magazine and factory ammo, along with the 8+2 MaGuts mag and reloads to see if I can duplicate the issue of light primer strikes I was having. I did hit the slide with some break cleaner, should I take the slide apart and see if there is a buildup of gunk preventing the firing pin from working properly?

Thanks Matt
 
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Hey Matt the sear shouldn't cause light strikes as the firing pin plunger assembly still has the same inertia.
I'm not sure brake cleaner is a good product for the slide, inside the slide is that plunger assembly and it is part plastic, not so sure the brake cleaner should be used in contact with the plastic.
It is possible that their is contamination in the slide area that houses the firing pin assembly or somehow a damaged firing pin and or weak spring.

Karl
 
Karl, Thanks for the reply, the Brake cleaner is Non-Chlorinated, I thought that was OK for plastic, but good point. I will disassemble the firing pin plunger and see what crud I can get out.
Thanks Matt
 
You can probably rule out the magazine. I can't see how the magazine would have anything to do with light primer strikes.

Which Apex sear did you install? The standard drop in replacement or the forward set sear?
 
You can probably rule out the magazine. I can't see how the magazine would have anything to do with light primer strikes.

Which Apex sear did you install? The standard drop in replacement or the forward set sear?

Apex two dot fully machined sear 100-063 (fixed part number)
 
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When you replaced the sear, did you re-adjust the trigger bar loop? If so you may have the timing off and the striker block is not completely clearing the striker when you pull the trigger. One way to check that is to remove the striker block and leave it out and see if the light strike condition goes away (this is only for testing, not a permanent solution) Before doing this, if removing the striker and cleaning the channel isn't part of your normal cleaning ritual, try doing that first.
 
100-036 is the part number for some magazine floorplates. I would assume you meant 100-063.

I'm not sure the sear has anything to do with your light strikes and it might just be coincidence that they started right after you installed the sear.

My best advice would be to disassemble the slide and give the striker assembly and the striker channel a good cleaning. After 2,500 rounds it could just be full of powder residue or dirt or whatever. If it were me, while I had it apart I would likely go ahead and install a new striker spring while I was there.

Best of luck. Hope you get it figured out.
 
When you replaced the sear, did you re-adjust the trigger bar loop? If so you may have the timing off and the striker block is not completely clearing the striker when you pull the trigger.

I knew this was possible with the forward set sear. I didn't realize this could happen with the normal sear.
 
When you replaced the sear, did you re-adjust the trigger bar loop? If so you may have the timing off and the striker block is not completely clearing the striker when you pull the trigger. One way to check that is to remove the striker block and leave it out and see if the light strike condition goes away (this is only for testing, not a permanent solution) Before doing this, if removing the striker and cleaning the channel isn't part of your normal cleaning ritual, try doing that first.

No I did not re-adjust the trigger bar loop, I will start with cleaning the channel.

Thanks Matt
 
100-036 is the part number for some magazine floorplates. I would assume you meant 100-063.

I'm not sure the sear has anything to do with your light strikes and it might just be coincidence that they started right after you installed the sear.

My best advice would be to disassemble the slide and give the striker assembly and the striker channel a good cleaning. After 2,500 rounds it could just be full of powder residue or dirt or whatever. If it were me, while I had it apart I would likely go ahead and install a new striker spring while I was there.

Best of luck. Hope you get it figured out.

Yes you are correct the part number is 100-063. Where is the best place to buy Shield parts?

Thanks. Matt
 
No I did not re-adjust the trigger bar loop, I will start with cleaning the channel.

Thanks Matt
Make sure all components of the striker channel and striker are bone dry. Do not lube any part in there. Also replace the striker spring while you have it apart. I had issues with light primer strikes as well with my MP C after Apex kit. I had to time the trigger bar and clean out the striker channel. All is well now. I did my MP9C and MP45C at the same time. I can't remember which I had the light strikes with. I believe it was the MP9C
 
Where is the best place to buy Shield parts?

I'm pretty new to the Shield so I don't have a good answer. I'd probably call S&W if I just wanted a striker spring. Or maybe check out Wolff springs website.
 
Apex customer service is great. The helped me sort out light strike problems with my Apex FSS installation on my old M&P40. Send them an email and they will help you figure it out!
 
Apex customer service is great. The helped me sort out light strike problems with my Apex FSS installation on my old M&P40. Send them an email and they will help you figure it out!

Thanks oldgray
 
I knew this was possible with the forward set sear. I didn't realize this could happen with the normal sear.

Hmmmm. Again, changing JUST the sear should have no effect on the striker spring and striker. I suspect cleaning, as well.
 
Thanks again to all who replied with suggestions. I cleaned out the striker channel and it seemed to do the trick.

Thanks Matt
 
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