Burwell DIY M&P trigger job

[Grizzlypeg]

Did the Burwell trigger job http://www.burwellguns.com/M&Ptriggerjob1.htm on my M&P40 and am very pleased with the results. It did not cut down the pull weight, as I didn't alter the sear surface, but it sure made it smoother and easier to shoot. I would highly recommend polishing the firing pin safety to eliminate that drag before the trigger bar engages the sear cam.

Here's a picture of my firing pin safety after rounding the edge with a stone. I then polished it to look like a mirror, using some scotchbrite pad (not seen). I also polished the trigger bar where it contacts the firing pin safety.

I cut back the cam surface and polished it as well, to eliminate the overtravel (further falling of the trigger after it activates the sear). This also shortens the reset after letting the trigger rise.

 

[Grizzlypeg]

Here's the part of the trigger bar that extends upwards and depresses the firing pin / striker safety. It's the key shaped grey part. Polish its upper surfaces smooth, as it rubs against the above illustrated part, and causes drag and grittiness prior to the trigger reaching the sear break point.

 

[Sinasta]

What did you use to polish the trigger bar?

 

[Grizzlypeg]

What did you use to polish the trigger bar?

An sheet of scotchbrite pad, sold for auto body work. Folded it over a ruler and went back and forth until the surface was polished. Didn't take long.

 

[Sinasta]

Can you take a picture of the top of the trigger bar and a pic of the other side for me?

 

[Grizzlypeg]

Can you take a picture of the top of the trigger bar and a pic of the other side for me?

I took some pictures (sorry, filthy mechanism) before I starting pulling it apart. Will those do? What would you like illustrated in the pictures?

 

[Grizzlypeg]

The sear mechanism prior to disassembly and modification.

 

[Sinasta]

Yeah I wanted to see if your trigger bar had rough edges as mine. Almost like it was pressed together where you can see a seam down the middle.

Thanks

 

[Grizzlypeg]

They wasted no effort in producing some internal components with all the aesthetic refinement of the key that used to come with a can of ham. However, it does function well.

 

[Winz]

I noticed you kept the mag disconnect. If you remove it and replace with a suitable spring, you'll find that the trigger bar won't touch the frame since you would have removed the mag disconnect and thus the cam action pushing the trigger bar to the right side of the frame.

I removed my mag disconnect pretty much the day I unpackaged mine. I did recall an immediate change in gritty feel.

 

[Grizzlypeg]

I noticed you kept the mag disconnect. If you remove it and replace with a suitable spring, you'll find that the trigger bar won't touch the frame since you would have removed the mag disconnect and thus the cam action pushing the trigger bar to the right side of the frame.

I removed my mag disconnect pretty much the day I unpackaged mine. I did recall an immediate change in gritty feel.

Got to get around to sourcing out a tiny spring to replace it. Removing it is definately on the to do list.

 

[Winz]

Got to get around to sourcing out a tiny spring to replace it. Removing it is definately on the to do list.

Good hardware store, motor shop, etc....

....or take a quality pump pen and check the spring inside.

Like I said, removing the mag disconnect would have pretty much eliminate the need of the polishing work of the trigger bar.

 

[Grizzlypeg]

Good hardware store, motor shop, etc....

....or take a quality pump pen and check the spring inside.

Like I said, removing the mag disconnect would have pretty much eliminate the need of the polishing work of the trigger bar.

Thanks.

I'm going to remove it because I don't want the mag disconnect to operate. I can't say I am feeling any drag owing to it, but maybe I will be pleasantly surprised when I remove it. When I operate the lower receiver, with the mag in place, and slide off, I don't see the trigger bar dragging on anything. Where should I be looking?

 

[Sinasta]

I dont have a mag disconnect on mine and I polished the trigger bar where it comes in contact with the striker block. Smoothed it right up.

 

[Winz]

Thanks.

I'm going to remove it because I don't want the mag disconnect to operate. I can't say I am feeling any drag owing to it, but maybe I will be pleasantly surprised when I remove it. When I operate the lower receiver, with the mag in place, and slide off, I don't see the trigger bar dragging on anything. Where should I be looking?

Yours may not be. On some of the M&Ps it seems that the trigger bar rubs slightly along the right side of the frame causing additional grittiness.

If yours doesn't, good to go.