Sear Housing Block Question
- Thread starter Dynamix
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Rastoff
US Veteran
Sure enough, if I pull up on my ejector, the block will tilt ever so slightly. I don't think it's an issue. The slide will hold it in place under use.
ggibson511960
Member
Me Too!!
Sorry to bump such an old thread, but I have the same problem, am about to dis-assemble to diagnose, and was wondering how your housing looseness turned out. Mine (on a 40c) isn't quite as loose as yours, but still has a discernable fore and aft wobble. I discovered it when trying to diagnose a gritty trigger pull. The trigger bar's first few millimeters of travel are very smooth. It's tilting the sear block housing. When the housing's rotation stops and the trigger bar is finally pushing on the sear, there is a pretty bad step in the trigger pull. My 40c has an external safety that wiggles up and down with the housing movement. That's how I first noticed this small defect. So here goes on surgery to do further diagnosis.
Sorry to bump such an old thread, but I have the same problem, am about to dis-assemble to diagnose, and was wondering how your housing looseness turned out. Mine (on a 40c) isn't quite as loose as yours, but still has a discernable fore and aft wobble. I discovered it when trying to diagnose a gritty trigger pull. The trigger bar's first few millimeters of travel are very smooth. It's tilting the sear block housing. When the housing's rotation stops and the trigger bar is finally pushing on the sear, there is a pretty bad step in the trigger pull. My 40c has an external safety that wiggles up and down with the housing movement. That's how I first noticed this small defect. So here goes on surgery to do further diagnosis.
ggibson511960
Member
Fixed!
Here's the report from the wilderness of shade tree gunsmithing. I couldn't wait, so tore into my 40c to see what was up with the sear housing block wobbling fore and aft. Sure enough, the fit between housing and polymer frame allowed the block to rotate aft when the trigger bar pushed up on the sear. There's nothing holding the block in place except the rear roll pin and front guide rails. The bottom of the housing is supposed to fit tight against a recess in the frame. Not so with the sloppy tolerances on mine, perhaps because it is somewhat of an oddity, having an external safety and a detent plunger and spring to index the safety. My housing just pulls right out of the frame without prying on the slide rails. I used some aerospace grade foil duct tape to make a tiny shim on the front bottom of the sear housing. It needed about 0.005 in. thickness to fill the gap and make the housing jam tight when in place.
Success! The block is firmly in place, doesn't rotate when pulling the trigger, and now I have a pretty decent pull without a big step in the force-distance curve of the trigger arc.
This is a minor design weakness that reminds me of No. 4 SMLE's. Early ones had a trigger mounted in the trigger guard that would float around when the gun got hot, making for a random and unpredictable pull, a zany design that got fixed later. Doesn't hurt much on the M&P where the pull was never intended to be a crisp single angle break. Probably no reliability improvement by doing this, but it cost nothing and took 30 minutes.
Here's the report from the wilderness of shade tree gunsmithing. I couldn't wait, so tore into my 40c to see what was up with the sear housing block wobbling fore and aft. Sure enough, the fit between housing and polymer frame allowed the block to rotate aft when the trigger bar pushed up on the sear. There's nothing holding the block in place except the rear roll pin and front guide rails. The bottom of the housing is supposed to fit tight against a recess in the frame. Not so with the sloppy tolerances on mine, perhaps because it is somewhat of an oddity, having an external safety and a detent plunger and spring to index the safety. My housing just pulls right out of the frame without prying on the slide rails. I used some aerospace grade foil duct tape to make a tiny shim on the front bottom of the sear housing. It needed about 0.005 in. thickness to fill the gap and make the housing jam tight when in place.
Success! The block is firmly in place, doesn't rotate when pulling the trigger, and now I have a pretty decent pull without a big step in the force-distance curve of the trigger arc.
This is a minor design weakness that reminds me of No. 4 SMLE's. Early ones had a trigger mounted in the trigger guard that would float around when the gun got hot, making for a random and unpredictable pull, a zany design that got fixed later. Doesn't hurt much on the M&P where the pull was never intended to be a crisp single angle break. Probably no reliability improvement by doing this, but it cost nothing and took 30 minutes.
Rastoff
US Veteran
Good for you. The pistol would have been fine without the "upgrade", but I'm glad you have a better pull now.
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