Any tips on Trigger mod?

Fired a hundred rounds of PMC FMJ through my modified 9ve today. I also allowed three others to shoot a mag each with it. They love the Hi-Viz sight I put on it. My son-in-law is going to buy one for his Glock. I Also shot a Barretta 40SW, new. The 40sw is a single action, and I have to tell you, that even though it had a nice grip, I did not like the amount of slack in the trigger, considering it is a single action. One guy had recently purchased an LCP and cut his thumb three times before realizing he had his weak hand placed wrong. What a bunch. But it was still fun.

My modified 9ve was smooth and without fault. I even rapid fired it, without a failure and put all shots in the black. The Hi-Viz is so bright it looks like it is powered.

Next step in the testing process will be to shoot hot ammo through it to see if I can induce a reset failure. I don't want to be presumptuous but I may have found the threshold of where you can make a certain amount of modifications and still not have failures. I will next fire some Federal and Win. Ranger +P ammo. I will continue to test it with boxes of cheap ammo also. Next weekend I will pick up a case of cheap ball ammo at a local gun show.

I believe that I may be ok with the mods I have made to the pistol. Only time and much much more testing will determine.

Once again, that new sight is really good. Even with my terrible eyesight, I had a good day.

I'm a new poster, but not new to guns or amateur gunsmithing.

The trigger pull weight of a gun, particularly a double-action (I'm not going to get into the debate about "it's not double action because it doesn't have a hammer"), is dependent on two things: friction and springs.

The design of the gun generally assumes that friction will go to near zero with use and then the springs will be the main factor. You can either put one or two thousand rounds through it, or you can mimic what that does and enjoy good shooting right away.

The SW40VE is well-designed, but rather cheaply manufactured, which means the out of the box heavy trigger-pull is mostly caused by friction, and I think that posters who are happy with the trigger out of the box probably got a smoother specimen than I did.

I've looked at the internet videos and seen that they mostly involve doing something with the springs. If the main problem is friction, then messing with the springs is breaking something that isn't broken, instead of fixing what is broken. I've got guns that are over 100 years old and still in good working condition, ball-point pen springs are not built to last 100 years in a gun.

The problem is not in the trigger but in the lower sear mechanism. The "gritty" feeling comes from there, as does a lot of the friction.

The sear in any gun is two metal surfaces like blocks that face each other under spring pressure when the gun is cocked and the trigger causes them to slide apart, abruptly releasing the hammer, or in this case, the striker. Technically the sear is the single part that holds back the hammer or striker tang but I'm using "upper" and "lower" here for clarity.

In the SW40VE the lower sear and sear housing are located in the rear of the frame. The lower sear is a cam which, when connected to the trigger by a simple metal link, will move rearward and downward, thus cocking the striker and then releasing it through a single trigger pull. The upper sear, or striker tang, is in the slide, connected to the striker.

The "grittiness" is caused by the fact that slot in the lower sear has been roughly machined, causing the bar that pushes the lower sear rearward to "chatter" through the machining marks. Also, the lower sear has an "S" shaped curve at the rear which interacts with a plastic ramp in the sear housing to drive the cam downward as it proceeds rearward. Again, rough machining marks here cause friction. The plastic is not the smoothest it could be, due to mold marks.

Finally, the surfaces of both the upper sear (attached to the striker in the slide) and the lower sear are roughly machined surfaces, causing friction.

So the real "trigger fix" is:

1. Smooth and polish the contact surface of the slot inside of the cam that is the lower sear

2. Smooth and polish the part of the lower sear cam that contacts the plastic sear housing as it moves rearward

3. Smooth and polish the mold marks on the plastic sear housing that contact the sear cam

4. Smooth and polish the contact surface (which contacts the upper sear) of the lower sear

5. Smooth and polish the contact surface of the upper sear (which contacts the lower sear) (you need to remove the striker from the slide to do this)

Some purists will object to 4 and 5, saying that the sear will be rounded and less crisp. But if you carefully polish the surfaces with the flat stick, that will be minimal. And a crisp sear is much more important and noticable in a single action than a double action.

WARNING: Do not use a power tool for these steps! It is too easy to remove too much metal.

I used a metal fingernail file from Revlon to get the machine marks out (thanks to my wife who gave it to me a long while back). I would say that the rough side is about 400 grit and the smooth is about 500.

Then I used a 600 grit "Angle Cut Sanding Stick" (works better when wet) from www.stevenshobby.com to polish the surfaces mentioned.

You need a jeweler's loupe or some other 10X magnifier to look at the original condition and to see when you have polished enough.

Finally, I lubed all contact surfaces (including the side of the sear housing that contacts the sear) with a Hob-E-Lube dry graphite and molybdenum (HL651). Look for a hobby store that sells electric trains, for this stuff. I like dry lubes or Rem-oil in guns because neither tend to collect grit.

I would say the trigger pull is now smooth and comparable to a Glock 23 or the new S&W SD (which has a redesigned rotating sear mechanism that has its own issues.) Not as good as a S&W M&P.45, which I have also fired.

I know this sounds like a lot of work, compared to changing springs. But when you change or remove springs you are redesigning the gun.

Since this is primarily a self-defense weapon; would you bet your life on a gun redesigned by you?

The other issue is, if you fire on someone in self-defense, your gun will be impounded and examined. Or even worse, God forbid, there is an accidental discharge and someone is hurt. You don't want to explain to a court why your gun has had factory parts removed, replaced or modified to make it easier to fire.

The "fix" I've described keeps all of the factory parts intact, just working the way they were designed to work after the gun is broken in. If you don't want to do this yourself but you want to improve your gun, then copy this post and take it with your gun to a reputable gunsmith. He (she) should be able to give you an estimate of cost based on the specific tasks I have outlined.

You will be shooting tight groups with this "horrible trigger pull" right away.

Happy Shooting!

PS: I originally did send the gun back to a S&W gunsmith under warranty complaining of the gritty and heavy pull even after 200 rounds. It came back with the note "replaced sear housing" and if anything, was worse.

Zebra:

Excellent post! I think you have it all covered.

If you plan on carrying your pistol concealed modifying the triggers is a slippery slope. I have heard prosecuting attorneys will often use the lightened trigger against you. Plus in the heat of the moment a lightened trigger may go off unintentionally. Of course if it will be a range or plinking piece....that's a different story. All of the above may be theory and conjecture but I don't want to take that chance. As others have said shooting it may help smooth the trigger and getting to know your pistol first isn't a bad idea.

Erich said:

Don't do it.

Seriously. As you say you're new to guns, I suggest you learn how to use them in their factory-issued condition before you start home-gunsmithing.

And it's "sear."

Click to expand...

THAT'S GREAT ADVICE FROM ERICH.........

Hey Zebra - post more, hombre!

Thanks for the kind words, Joe!

What the said:

If you plan on carrying your pistol concealed modifying the triggers is a slippery slope. I have heard prosecuting attorneys will often use the lightened trigger against you. Plus in the heat of the moment a lightened trigger may go off unintentionally. Of course if it will be a range or plinking piece....that's a different story. All of the above may be theory and conjecture but I don't want to take that chance. As others have said shooting it may help smooth the trigger and getting to know your pistol first isn't a bad idea.

Click to expand...

Interesting. I spent a lot of time in court and have NEVER had any prosecutors question the action of a fire arm. Things must be different today. I would be glad to go to court and explain my mods and then ask what if anything it had to do with self defense. I also read a lot of news articles related to shootings and have yet to find one where someone modifying their weapon was even questioned. If anything modification to a weapon would be a possible DEFENSE against Accidental shooting, not self defense. Just saying...

As far as accidental discharges, these aren't single action weapons. You are more apt to have an AD with a single action weapon than a double action weapon. You still have two safeties on this weapon that prevent accidents. You would have to be real nervous to pull a double action trigger to the point of firing.

AD is not a factor in these modifications. Fail to fires are the only factor in these modifications.

One point that I would like to point out regarding the use of ball point pen springs. Many mods consisting of using the pen spring, merely replaces the outer spring on the sear. NOT the inner spring. The old Sigma apparently did not have the outer spring. I may be wrong on that point. But, if you are merely replacing the outer spring, the one that keeps the inner spring fairly straight, then the pen spring is still serving it's purpose. If you eliminate the inner spring, then I can see where the problem would exist.

The striker spring is the one that provides the power to the firing pin, not the sear. I am not an expert but the way I see it, the only thing that would happen if the trigger or sear springs being replaced would do is cause a failure for the trigger to reset, rendering the pistol useless.....not dangerous.

There seems to be a lot of debate over (spring)modifications. The way I see it, the worst that can happen if you modify the springs, is you render the pistol useless. I see no way that you are going to make it dangerous or cause it to fire prematurely. This is a double action and you HAVE to draw the striker back in order for it to fire. If you have an accidental discharge, then you shouldn't be firing any pistol while you are that stressed.

I do actually agree that the sigma will become smoother as it wears. I also agree that the springs will become weaker and thus an easier trigger pull. Some folks don't want to fire thousands of rounds before they achieve that result. They can't afford a better, more expensive pistol that will give them that action, so they expedite the wear by making mods.

I respect the "purist" view. I also respectfully disagree that ALL mods are dangerous. Many folks come aboard this forum to ask for advice on how to modify their weapons SAFELY.

There are plenty of forums out there that argue which is better the Glock or the Sigma. There are plenty of threads on HERE where folks expound on how they get a thrill every time they fire their Sigma, or get a chill up their legs. You know, all that girly talk....just kidding.

I don't know about others on here but I frequent this forum to learn about ballistics, reloading, preferred holsters, new sights, AND improvements. Improvements to the function and operation of my 9ve by means of modifications. Other, more expensive pistols have after market parts readily available to make their weapon function even better. Unfortunately, the Sigma does not warrant such favor in the after market industry so many mods are a result of back yard mechanics. I peruse the forums in search of "results" from these modifications. I want to know how far the ceiling has been stretched before failure resulted. That way, I will have no need to invest time in these experiments and can aim in a different direction with my mods.

Many folks have been successful with their mods but are reluctant to comment in fear of being criticized for corrupting the "stock" design.

Believe me when I say that just because I enjoy "plinking" in the back yard, I am sure that the same round that punches a hole in paper will also work quite satisfactory as a defense in exigent circumstances. Reliability? Well, so far I have had NO failures. I have one question though. How many rounds do I need to fire through my modified Sigma before it will be deemed "dependable?" I have heard of Sigmas out of the box that have had failures, that are factory standard.

The purpose of my diatribe is not to argue the dependability of a factory standard pistol. My purpose is only to recognize that not everyone wants or intends to maintain it at factory standards. Many feel that a weapon, like any other machine can be improved and/or personalized. I imagine that is the reasoning behind new sights, painting the slide, new grips, etc.

I've been a prosecutor and have reviewed hundreds of criminal cases as an appellate lawyer, and have never seen this be an issue either - but I'm not going to get into it.

It's unlikely to ever be an issue, but it's certainly not impossible that it could be one under the right circumstances - no sense discussing all the possibilities (who's got the time to waste?) here.

I've had work done on a number of my guns' triggers, and done some myself. Do whatever you want, but you may have to justify it and you will definitely have to be responsible for what you do.

Working with the original trigger is going to make a strong trigger finger.
Working the trigger is going to make a better trigger.
I got my trigger strength from a BB gun but still removed the pigtail. (I think reset speed enters only when really fast firing. My fingers can't go that fast.)
I polished every part I could get to, taking care to not do much to the sear. Polishing the barrel ramp is important, again not changing the shape.

It holds and shoots so-o-o nice.