Better trigger - w or w/o thumb safety?

[nanney1]

I read somewhere, maybe here??? that there was a trigger difference in M&P's depending on whether or not you had a model with a thumb safety. One was a slightly better trigger pull than the other. Or maybe it was just for certain models - Shields maybe?

I want to say that versions with the safety were better, though that seems counterintuitive.

 

[Rastoff]

I don't know where you heard this, but it's absurd. The thumb safety cannot affect the trigger feel or quality in any way.

Here's how it works:

In this image, the red arrow is pointing to the thumb safety and the green arrow is pointing to the trigger bar. The thumb safety is On here.

As you can see, there is just a little tab that prevents the trigger bar from moving back. That's all it does.

Here it is in the Off position:

In no way can it affect trigger feel or quality. It ONLY blocks movement.

 

[Pete_H]

The sear housing block for the thumb safety guns is different from the non safety guns.
The Apex trigger kits have a better felt reset and crisper break in the non safety SHB.
Not conjecture, I have both and can attest to the variation. Even upgrading the SHB on the safety gun gave marginal results, ie: the reset was barely perceptible and the trigger break was bordering on vague.
The non safety gun has an excellent feel.
I backed some of the mods out of the safety gun as it was no fun to shoot. YMMV

 

[nanney1]

The sear housing block for the thumb safety guns is different from the non safety guns.
The Apex trigger kits have a better felt reset and crisper break in the non safety SHB.
Not conjecture, I have both and can attest to the variation. Even upgrading the SHB on the safety gun gave marginal results, ie: the reset was barely perceptible and the trigger break was bordering on vague.
The non safety gun has an excellent feel.
I backed some of the mods out of the safety gun as it was no fun to shoot. YMMV

OK, I thought I had read something along those lines. I have a Shield with a thumb safety. So, basically, the trigger isn't good and upgrades do little to help... correct?

 

[Pete_H]

I would say improvements could be made depending on your requirements.
There is a lot of upside potential. Even a thousand rounds can have a substantial impact.
Call APEX they are very informative.

 

[Rastoff]

Hmmm, you'll have to give us a little more Pete_H. Yes, the sear block is different, but only to make room for the detent and detent spring. I'm not seeing how it could affect trigger pull.

In your comment you also said that you felt the difference when installing an Apex kit, but didn't comment on how it was prior to the kit. Is there a possibility the kits were different? I know there are differences in how the "candy cane" is adjusted.

I'm not questioning your results. I believe that one trigger is better than the other. I'm just curious as to the why.

 

[Pete_H]

Both kits were 100-024 polymer trigger with forward set sear.
One 40c w/ thumb safety and one 9c without.
The apex'd 9c has been perfect through 700 rounds.
The 40c required an upgraded SHB with larger sear plunger to begin to feel the reset. Even then it was too light with the heavier trigger spring.
The non thumb safety SHB can accommodate a spring and plunger to aid reset feel, the thumb safety SHB does not have this option.
The 9c did not need this, it had a distinct reset after kit install.
You are welcome to shoot both guns, disassemble them and explain it to me also. I realize that the mechanical interaction we are discussing should be separate from the mechanism controlling the safety.

 

[Rastoff]

Are these very early guns? The original sear block had a very small sear plunger and spring. Later S&W upgraded it to a larger spring. The sear plunger and spring are not part of the reset so, changing that spring doesn't affect reset.

The Apex Reset Assist Mechanism (RAM) only fit in the earlier model sear blocks because they are the only ones with the hole for the RAM. None of the later sear blocks, with or without thumb safety, can accept the RAM.

So, even if the sear block is the difference in yours, it won't be in the newer models. The 2.0 is different yet.

 

[Pete_H]

Yes the 40c is earlier and I did upgrade the SHB and SP from SSS.
Neither gun will accept the RAM.
Thanks for the lesson!
I am removing the thumb safety and plugging the frame on the 40c as an experiment. I have plenty of safety guns for that role.

 

[Rastoff]

Let us know how it goes. I'm very interested.

 

[forrestinmathews]

How to get a "better" trigger:
Install the Apex striker block with lighter spring. This smooths out the pull a bit.
Install the Apex Competition Spring kit (still sets off CCI primers no worries).
Disassemble the lower portion of the trigger and sand the polymer spring leg carefully.
OR
Install Apex FSS kit ( clip a coil and a half off the trigger safety spring if using competition spring kit).
Radius the edge of the initial third of the "teardrop loop" disconnector where is meets the sear. (Helps with reset if you open the loop)
Caution:
Carefully sand the polymer spring leg in the lower portion of the original trigger. Take your time. Just enough so that it disengages in proper sequence during the trigger pull.
Carefully clip the trigger safety spring until it eliminates the catching on the frame during a proper trigger press. This happens when the spring in the safety is heavier than the trigger spring itself.
Check the striker for peening if you open up the trigger bar loop. You can have some gains in lessening pretravel and cleaning up the trigger pull feel, but you can get the striker block safety out of sequence where it isn't fully disengaged before the striker falls. Especially likely with the FSS kit. If you're getting light strikes and have opened the loop, close it a little and your problems will likely disappear.

 

[Rastoff]

Carefully clip the trigger safety spring until it eliminates the catching on the frame during a proper trigger press.

If the trigger safety tab is catching on the frame during a normal trigger press, your gun was not built properly or the tab or frame is out of spec. Send the gun back to S&W for repair.

You should never have to modify your gun to make it work correctly.

 

[forrestinmathews]

If the trigger safety tab is catching on the frame during a normal trigger press, your gun was not built properly or the tab or frame is out of spec. Send the gun back to S&W for repair.

You should never have to modify your gun to make it work correctly.

If you read carefully you'd see that with the Apex competition spring kit and the FSS kit, which aren't to be used together according to Apex, you'd have to make that modification. We're on the customized end here, far from stock.