How can I increase the trigger pull?

[BSA1]

I have a M&P 1.0 9mm. We brought it new with a APEX trigger already installed. Recently I became concerned about how light the trigger pull so I took it to a local gunsmith and the trigger pull measured 3.0#. As this is for home defense I want around a 4.5# trigger pull. The gunsmith adjusted the trigger to about 3.8# which is still lighter than I want. (I measure less than that with my spring trigger gauge). I am not sure the gunsmith understands why a self-defense gun needs a heavier trigger pull.

So how can I increase the trigger to 4.0#+? I don’t see springs on the APEX web site. The trigger itself is fine so I want to avoid having to buy their complete Duty Trigger kit.

 

[WR Moore]

You might call Apex and speak directly to them about what you want. It's possible that the previous owner installed the Apex sear kit and trigger. That being the case, returning some parts to original S&W might help. The original factory trigger went about 6.5 lbs. Easiest way to do that would be to install a factory sear block (contains sear & springs) and trigger assembly. Or at least the trigger bar and spring and reuse the Apex trigger.

Again, talk to Apex.

The intent of the M&P 1.0 was a trigger very much like a superbly tuned double action revolver. I liked my issue gun very much. You neither need nor want a light short travel/short reset trigger for defensive/duty use. Best of luck.

ETA: not every shooting is going to result in your firearm being examined by the crime lab to make sure everything is within factory spec. But, you can bet your house, pension, IRA & 401K that if there's a civil suit, plaintiff's counsel will get someone to do so.

 

[BSA1]

It has a APEX trigger. I don’t know whose parts are in it. The factory 1.0 I have trigger pull is 5 3/4#.

Call to APEX Monday is a do.

 

[NewLiberty]

Look at the Duty/Carry action enhancement kit from Apex.

 

[BSA1]

I am trying to avoid buying their entire Duty/Carry kit as I think (hoping) changing the springs will do what I want.

The problem with ordering a factory spring is the cost of shipping.

 

[WR Moore]

The trigger didn't get down to 3 lbs with spring changes alone. After poking around on the Apex website, I expect the previous owner had the competition enhancement package installed. If you go to the Apex site, you'll see all the parts involved, but they do include sear and sear spring as well as some other parts.

 

[Bullseye Smith]

Buy a spring kit from S&W and replace them, when you take the slide off you will see them.

 

[BSA1]

The trigger pull on my nib 1.0 9mm is 5 3/4# which is heavier than I want. I would like about 4.5# trigger pull so seems like going back to all factory springs will be heavier than that.

I also suspect a competition trigger kit is installed on it. Which part affects the trigger PULL the most?

Is the trigger return spring is just for the trigger reset? If so I can ignore it as there is not a problem with the reset.

Could the trigger bar been overpolished or thinned to give the light trigger pull?

Of course the sear itself could be overpolished or too much removed.

What is the relationship of the sear release lever?

The “gunsmiths” in my area all seem to be focused on how light they can get the trigger pull. Working on the action seems to be within my gunsmithing skills. Just need to decide what parts to focus on.

 

[WR Moore]

The sear release lever only lowers the sear to allow slide removal. No effect whatever on weigh of trigger release.

You are correct the only function of the trigger return spring is to return the trigger & trigger bar to the at rest position. However, it also has to get past the striker safety plunger and spring.

The trigger bar may/may not have been reconfigured or may be an Apex product.

The sear will have been specially machined by Apex from appropriately heat treated steel. The striker safety plunger is also an Apex product as are the springs for each.

I repeat, the easiest way to address your problem is to replace your sear block with a factory sear block and go from there.

Now for the non mechanical part of the question that you apparently don't want to hear. I spent better than 25 years as a certified law enforcement firearms instructor. You neither need nor want a trigger press lighter than factory stock for self defense. You don't need to shoot itty bitty, teeny weeny groups to defend either yourself or others. You do need to practice.

For commentary on the subject I give you a court accepted expert witness on use of force who does numerous trials each year:
Facts About "Light Trigger Pull Liability"

 

[NewLiberty]

Numrich currently has M&P complete sear blocks, along with trigger bars & triggers. Buying one of each would be cheaper than the Apex Duty/Carry spring kit.

 

[BSA1]

I plan on calling APEX and discuss this with them. If it is originally a competition kit than going with their Duty/Carry kit may be the way to go. I am trying to understand the trigger bar, sear and spring relationships before ordering parts.

WR Moore,
You are correct that I don’t want to hear about light trigger pulls. I know all of the arguments. Just why do you think I want to INCREASE the trigger pull? Don’t get me started about my opinion of Ayoob. It went out the window in a murder case he testified in. But since you think so highly of him in the article you linked he cites 4.5# trigger pull for the 1911 as being defensible in court.

p.s. I was a Police Firearms Instructor, NRA Firearms Instructor and manager of indoor shooting range. So don’t get me started on the ability of leo’s to safely handle and accurately shoot a handgun.

p.s.s. The topic is about gunsmithing. The politics of how light a trigger pull is indefensible would be best discussed in the Concealed Carry and Self Defense Forum.

 

[WR Moore]

Sorry about that, but we get a lot of folks here with, shall be say, limited experience.

With regard to your desires, the earlier check of the Apex website showed the Duty package with a 5-5 1/2 lb pull. So I'm not the only one with concerns about weight. However, if Randy's good with that weight, you should be OK.