M&P sear reset failures with Apex FSST kit

Do you have the late style sear block or the early style? Early ones have the 1/16th sear return spring, later ones have the 1/8th spring, Apex recomends the later set up for all M&P's being fitted with the FSST, because the early set up can cause failure to reset.
 
Do you have the late style sear block or the early style? Early ones have the 1/16th sear return spring, later ones have the 1/8th spring, Apex recomends the later set up for all M&P's being fitted with the FSST, because the early set up can cause failure to reset.

Early style, so I couldn't install the 1/8" spring that came with the kit. I ordered a sear block from Brownells figuring they would be selling the later version, but what arrived is exactly like the one I have. I'll try increasing the trigger over travel, and if that doesn't solve this, I may have to get a smith to drill out the spare sear block to accomodate the 1/8" spring.

Strange behavior tho. The reset failures appear to be totally random.

M
 
Apparently it needs to be milled, as the larger hole isn't on the same centre as the smaller hole - at least that's what I heard from Randy. Try calling Murray Charlton and asking if he has any of the new style in stock (and tell him why) - I'm surprised Brownells shipped the old style
 
I haven't had any issues with mine, but I believe mine was the late version :confused: However, when installing this, I lost the takedown lever retaining wire so my lever keeps falling out when I disassemble the pistol. It's a PITA so watch out! (Anyone know where I could pick up such a part?)
 
I haven't had any issues with mine, but I believe mine was the late version :confused: However, when installing this, I lost the takedown lever retaining wire so my lever keeps falling out when I disassemble the pistol. It's a PITA so watch out! (Anyone know where I could pick up such a part?)

So that's why my takedown lever comes off now. What does that wire look like?

M
 
Brownells sent me a complete M&P sear block housing so I would assume the retaining wire would be a go. Brownells currently show out-of-stock for the wire. I checked once I realized mine was AWOL as well:-&

M
 
I was mistaken, the sear block housing from Brownells does have the 1/8" sear spring upgrade. You have to look at both blocks side-by-side to tell the difference. So, I swapped the housings and install the APEX spring. With luck my dead trigger syndrom has been resolved.

M
 
When I thought I was going to have to track down an updated sear housing block I contacted APEX and Murry Charlton to see if they could help me.

APEX responded that they don't accept any orders or work from out side the US.

M Charlton responded a week later, indicating that their supply of sear housing blocks is on back order.

M
 
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Found the retaining wire! It's only 1.2 cm long and looked like a bent staple so it was a lucky find...

Oh Oh, I scanned my work area with a magnet and came up with numerous staple looking things, thru them all out!

On the plus side, Brownells has stock and I ordered three.

On the down side, replacement requires pulling the trigger AGAIN!

M
 
I know. What a PITA, especially that damn trigger spring that the forward roll pin has to go through. Oh well, at least I won't have to go searching for that takedown lever.
 
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