Another SIgma trigger thread

[hodadd]

First time post. Long time lurker, but thought I might add my .02 here.

I was going to post this on an existing thread, but it is kinda long, so I decided to start anew.

It seems to me the problems with the Sigma trigger is a combination of issues.

The striker spring is too stiff. They claim it is 4# and Wolff offers a 3.5# replacement. However, Wolff is known within the industry for making good springs, but their rating system is inconsistent and suspect. So, relying on their rating system is not wise.

After reading about the striker spring, and being a long time Glock user, I took one of my old Glock striker springs and tried it as a replacement. It is too long, but it is usable. However, it does not allow full movement of the striker, so I cut it to the same length as the Sigma spring. I installed it and tried it (dry firing only) and it seemed to lighten the trigger pull quite noticeably. I will take it to the range and see what happens. I do note that it still sounds like it is delivering a solid hit to the (potential) primer.

Nextly, the trigger reset spring is too stiff. Not by a lot, but seems overly stiff for the application. It looks like, once again, a Glock spring might work. I will investigate that further, unless someone has specific input.

As to the three springs in the sear assembly. The pig tail spring does seem like it does serve a useful purpose, as stated, under extreme recoil situations. So, it's removal is problematic. The two nested springs are interesting to me. If you look closely at the construction, you'll notice the assembly moves in two plains; up and down, and front to back. A coil spring is usually only designed to work in a single plain. I believe this is why they inserted the pig tail spring, as an assist. So, to if you notice, the coil spring is off set and does not sit within the assembly in a straight axis. Flat out, this is poor engineering. This is why the springs appear to squish and potentially bind in operation. The better solution, without re-engineering the sear assembly is, IMO, not to remove the outer guide spring, but to remove both springs and use a larger diameter (outer) spring, with the proper weight of "pull". This will eliminate the possible binding from an improper diameter spring; given the offset. Of course, that's the rub: finding the proper weight spring to do the job, since the inner spring appears to be the working member. I am in the process of searching for one, but have not had the time to complete the task.

However, I will post my findings as they become available.

[hodadd]

First time post. Long time lurker, but thought I might add my .02 here.

I was going to post this on an existing thread, but it is kinda long, so I decided to start anew.

It seems to me the problems with the Sigma trigger is a combination of issues.

The striker spring is too stiff. They claim it is 4# and Wolff offers a 3.5# replacement. However, Wolff is known within the industry for making good springs, but their rating system is inconsistent and suspect. So, relying on their rating system is not wise.

After reading about the striker spring, and being a long time Glock user, I took one of my old Glock striker springs and tried it as a replacement. It is too long, but it is usable. However, it does not allow full movement of the striker, so I cut it to the same length as the Sigma spring. I installed it and tried it (dry firing only) and it seemed to lighten the trigger pull quite noticeably. I will take it to the range and see what happens. I do note that it still sounds like it is delivering a solid hit to the (potential) primer.

Nextly, the trigger reset spring is too stiff. Not by a lot, but seems overly stiff for the application. It looks like, once again, a Glock spring might work. I will investigate that further, unless someone has specific input.

As to the three springs in the sear assembly. The pig tail spring does seem like it does serve a useful purpose, as stated, under extreme recoil situations. So, it's removal is problematic. The two nested springs are interesting to me. If you look closely at the construction, you'll notice the assembly moves in two plains; up and down, and front to back. A coil spring is usually only designed to work in a single plain. I believe this is why they inserted the pig tail spring, as an assist. So, to if you notice, the coil spring is off set and does not sit within the assembly in a straight axis. Flat out, this is poor engineering. This is why the springs appear to squish and potentially bind in operation. The better solution, without re-engineering the sear assembly is, IMO, not to remove the outer guide spring, but to remove both springs and use a larger diameter (outer) spring, with the proper weight of "pull". This will eliminate the possible binding from an improper diameter spring; given the offset. Of course, that's the rub: finding the proper weight spring to do the job, since the inner spring appears to be the working member. I am in the process of searching for one, but have not had the time to complete the task.

However, I will post my findings as they become available.

[varoadking]

Well done...

Well over my head as well, but glad to see bright cats like you workin' on stuff like this. You oughta furnish Smith with your engineering expertise...

The trigger pull is the only blemish on this otherwise very servicable firearm...

[tonytgman]

hodadd; you do not need to find a single spring for the sear. There is already a spring there to do the job, this is the inner spring of the two. Just discard the outter spring and that will take care of any binding problems you may encounter as well as lighten the amount of trigger pull... I do hear from other people that the pigtail spring is not needed, however, I do believe that it is neccessary. Read my post on the (pictures of sigma internals thread), last few pages I believe, for more info on how to lighten and shorten the trigger pull. BTW I do not really suggest changing the striker spring although it can be done and may lighten the trigger pull slightly, it will cause FTF's.....

[jmlock]

I'm glad to see guys out there tinkering with these guns. I've read the other threads also, but I just can't modify mine (40VE) when I carry it on my hip. But, I've put it through it's paces at the range and I've noticed the trigger pull loosen up a bit. Not like my Glocks, but still good and reliable enough for me to carry. No failures at all with this pistol.

[OKFC05]

I can save you some time on the Sigma.

As an IDPA match director, several years ago I contacted a MA IDPA match director (who is a S&W engineer) about modifications being made to Sigma pistols showing up at IDPA matches and got a good briefing on the design (and problems) of the Sigma trigger. He explained what each spring does, why it is there, and what the failure modes of the gun are.

First, the striker spring is calibrated to fire any commercial ammo, but is not like the Browning HP in being able to fire any 9mm ammo ever made. The failure mode of a lightened striker spring is failure to fire. While legal for IDPA, it is NOT a good idea to lighten the striker spring.

Second, the inner sear spring is the basic spring that returns the sear to catch the striker when the slide moves forward. If only standard or mild +P ammo, like Gold Dot, were used in the Sigma, this spring would get the sear back up in time to reset. The failure mode as one approaches +P+ or "LEO only" hot loads is that the sear fails to reset, which means it becomes a single shot.

Third, the outer sear spring was added when it was determined that customers were going to shoot whatever kinds of loads they wanted regardless of S&W statements or cautions. The "overload spring" on the sear assures that even with Win +P+ the sear will rise fast enough to catch the striker and reset for the next shot. Removing this outer spring is legal for IDPA and is commonly done. If appropriate standard and mild +P ammunition is used, the gun works fine forever. However, since the shooter can use any hot ammunition he wants, for legal liability reasons neither S&W nor I can recommend you make ANY modification to a gun used for defensive reasons.

Fourth, the pigtail keeps the sear pushed into proper alignment at all times. The failure mode for its removal is subtle, since it does make it fail every time, but can be erratic. No amount of "range testing" will assure that the next shot will not be the one that acts up. If the side bearing surfaces of the sear are smoothed, the pigtail adds little to the pull weight.

Lastly, there are some surfaces on the sear that can stand some hand polishing to speed "break in" and aid smoothness. It is not easy to see exactly what rubs where when it is apart, but it can be done with a little care.

My concern is that people are trying to re-engineer the Sigma trigger without understanding how it works or what the failure modes are. Particularly important is that the gun can work fine forever with range ammunition and fail with hot defense loads. Trading in a modified gun increases the chance the new owner will find himself with a single-shot in a bad situation, so I encourage everyone to return the springs to stock before tranding in any Sigma.

I hope this information helps people who want to lighten and smooth the Sigma trigger for their personal use, and prevents people turning a very reliable pistol into a "boobytrap."

[Jim H]

Originally posted by OKFC05:
I can save you some time on the Sigma.

...I hope this information helps...

Thank you for taking your time to post this valuable information!

[Andy Taylor]

I have a very early 9mm Sigma. I inherited it from a friend who put his money down when the .40 came out and got the first 9mm the dealer could get. My friend had told me that he had shot many thousands of rounds through the gun and eventually the trigger spring broke. He sent it back to S&W and they replaced the spring. I have noted that the trigger is much nicer on this Sigma than any other that I have tried. I have only put a couple hundred rounds through it myself but it has not given me any problems. It is mainly a range gun and it holds to much sentimental value to use for anything else. My question is, was there a change in the trigger between the early guns and the later ones? Or is the better trigger simply a result of all the use my friend gave this one?

[Erich]

OKFC05, thanks very much for a great post.

[jmlock]

That is some very good information. Thanks.

[hodadd]

Thanks for your input OKFC05. While, I don't take issue with anything you said, I will add some other observations.

The nested springs do operate as you said; however, they perform other functions as well. As I termed it in my original post, the outer spring does act as a guide, but not stated in my original post, so too does the inner spring. They work together, in that the inner spring is too long. It has a significant amount of pre-load. I believe too much in fact. And, what keeps it in place during operation is the outer spring, and the recess on the sear and nipple on the outer holder. My concern about removing only the outer spring is that since there is so much pre-load the spring at rest and under operation (remembering the spring is working under two differing planes of operation) it bows outward. This could very easily lead to the spring becoming displaced under operation. The problem I've found about removing either spring is the design, which realistically requires both springs, or better said, two springs.

I tried the ink pen spring to replace the outer spring, but it does not offer enough tension to hold the inner spring properly. Another possibility is to trim the inner spring to remove some of the pre-loading. However, I'm not ready to do that just yet. What I am attempting to do is to find the proper spring to replace the inner spring and let the outer spring do the work, and just let the inner spring be a passive unit, serving the only purpose of holding the outer spring in place. Because without the inner spring, the outer spring will not stay in place during operation.

I still maintain that part of the problem is those two springs are redundant and being so, they are over sprung. Which, BTW, is a common problem in almost all new S&W (among others) products.

I also generally agree with your comment about the striker spring, except I do think it is too stout. I compared the draw weight of the strikers on my Sigma with my Glocks and found the draw weight to be significantly higher on the Sigma as compared to the Glocks. Since the Sigma is clearly based on the Glock and their designs are so similar, they should have similar draw weights on the strikers. The only difference being, the Sigma has a secondary striker spring to make the striker retract after striking the firing pin. This was clearly done to eliminate the striker being drawn across the primer as the pistol cycles, like Glocks do; and allows the Sigma to have a rounded firing pin, rather than the blade shaped firing pin of the Glock. This secondary spring is very weak, so it should not require much additional force to overcome.

Remember, even if you take the numbers from the Wolff spring website as accurate, by decreasing the striker spring from 4.75# to 3.5#, you are decreasing the weight by a huge percentile. I would maintain that decreasing it by only, from 4.75# to, say, 4# or 4.5# is adequate to accomplish the task. Hence, the Glock spring.

[Camprunner]

Why dont you guys just leave the Sigma alone and just "Shoot it" If you want a better trigger then buy a M&P or a used 5906 or something. When I bought my Sigma I pulled the trigger and said yep it's hard but I still think it's the best $$$ I ever spent and as for the rest of you ladys if you can't pull the darn thing and get it on target then buy another gun.

[Erich]

I am also a fan of leaving things like this alone, myself. I shoot my SW9GVE as a 17-shot double-action revolver, not as a speedgun.

But, Camprunner, you have to admit that OKFC05's description of the mechanism was interesting. I'd never mess with my Sigma's springs, but I enjoyed learning about the gun nevertheless.

[Spotteddog]

It was a great description! There's little chance I'll ever see one torn down. And an even smaller chance of me working on one after being torn down? But knowledge IS power! And being able to make educated guesses from time to time because you DO know it's operation, sure can help out someone. Especially when it won't go bang.

[Camprunner]

Yes Erich I must admit OKFCO5's post is a good one and I guess I should not talk I do have two Ruger 10/22's that I did extensive mods to.

[Mickstix]

First, I think it would be neglectful, if not criminal, to trade or sell any gun that's had ameture gunsmithing mods done to it w/o disclosing such at the time of sale.. (even though any responsible gun buyer/owner should put his or her sd weapon through its proper paces at a range before entrusting it to save their life) That being said, why do people care if we tinkers like messing with "our" guns?? There's always a few who like to badger the guys doing the leg work and posting their findings on making these guns more pleasurable to shoot.. We do it for the same reason we change the carbureators and jets on our old chevy small blocks.. We want them to run better, and for less $ than it would cost to buy an already souped up version.. Is that really so hard to understand?
Thanks to you guys who continue to tinker with these guns, and let us in on your findings!!

[MK]

Originally posted by Lucky Derby:
My question is, was there a change in the trigger between the early guns and the later ones? Or is the better trigger simply a result of all the use my friend gave this one?

The first "F" series Sigma did have a different
trigger. Many here have mentioned that it feels
better than the newer VE models.
The change was mainly due to the lawsuit with
Glock I think.
I guess the original was too close to Glocks
design, and they changed it as part of the
lawsuit settlement.
Or that's my take anyway..
I've never changed my springs, and probably
won't being I depend on mine for defense.
I did do some very light polishing though.
I can shoot mine fine as is, so can't see much
point in going farther. I actually prefer the
slightly stiffer trigger as it's a bit of extra
ND protection. The only part I'm picky about
is that the trigger pull feels exactly the
same every time. That's why I did some polishing
around the sear areas. Mine was catching a bit
due to a very sharp edge on the striker, and
sometimes if you did a slow pull, you could
pull all the way back, and still not release
the striker. After I polished that sharp edge
down to a slightly less sharp edge, it seems to
work as designed. Doesn't hang up due to the
razor sharp edge, and the release point is much
more consistent.

[ZO6Vettever]

Originally posted by Camprunner:
Why dont you guys just leave the Sigma alone and just "Shoot it" If you want a better trigger then buy a M&P or a used 5906 or something. When I bought my Sigma I pulled the trigger and said yep it's hard but I still think it's the best $$$ I ever spent and as for the rest of you ladys if you can't pull the darn thing and get it on target then buy another gun.

Amen! My Sigma has just under a thousand rounds down the pipe and has been to S&W for trigger work around the 400 mark, they said they "adjusted the trigger". I don't know what they did but it's better, way better. The pull is smooth, still long and hard but with no more of the "when the hell is it going to go bang" feeling. I found if you pull the trigger like you mean it instead of squeeeezzze, it is fine. Think double action revolver. It's not designed to be a match pistol but a DAO handgun and it's a damn good one. My neighbor just got an M&P 9mm compact. The trigger is way light and short for a gun with no safety, we both agree S&W should have a safety on all of them.

[Camprunner]

I went to the range the other day with my 16 year old nephew who has never fired a gun in his life. I brought my SW9VE and my 5906 I let him shoot the 5906 first and he did quite well then I let him shoot the Sigma and I had to laugh. He was like pulling the trigger and he had that look on his face like "ok now nope" "ok now nope" pull a little harder "NOW---BANG" I think the first few shots sort of shocked him but once he fired a few clips he was dead on target. As for me I don't mind the long hard pull once I fired about 300rnds threw it and got rid of the sort of sand fealing that is.

[hodadd]

UPDATE:

I worked my way through my spring collection trying to find the ideal spring and/or combination of springs, AND I think I hit upon a winner.

Caveat: I have A LOT of springs. Some of which are marked and some are not. Some are in bags from previous project guns (of which there are many) and some are just loose.

The spring I found (I am almost positive) is the spring from the plunger tube of a .45 government model. It is the proper diameter, being the same size as the inner sear spring. However, it is a stronger/heavier and longer spring. But, that's what I was kind of looking for; thinking of eliminating the redundant nature of the nested springs. So, what I did was to cut the spring, so that it had minimum pre-loading; and by doing so, that reduced the amount of deflection (squishing out sideways) of the spring. This seems to eliminate the risk of the inner spring becoming dislodged during normal operations, and being a stronger or heavier rated spring, seems to provide adequate tension on the sear assembly. And, by doing it this way, I re-installed the pig tail spring and was able to maintain an excellent trigger pull. (Long and kind of squishy, but much lighter with a very clean and crisp break.) (ALSO, bear in mind, this is with the cut down Glock striker spring installed.)

I am extremely pleased with the results. HOWEVER, I have not taken it to the range to make sure it goes bang and does so consistently. Due to my work schedule I will not get that opportunity for another week or so. I've been squeezing this project in, in my off time. I will posted the range results when available. But, I am very optimistic that this will work.

As a side note, during my tinkering I noticed that I believe I also discovered the reason for the grittiness of the trigger that we all have experienced. I did not do any polishing (yet) on any part, but by doing my trigger mod, I eliminated the gritty feeling. What that tells me is the parts are over sprung and excessively stressed (if you will) causing the parts mating surfaces to feel every tiny imperfection. By reducing the spring tension, you take the excessive tension off of the parts so they no longer feel gritty.

[tonytgman]

hodadd & everyone; if you do my mod with the .010 sear ramp plate you will find that not only will it shorten the amount of trigger travel but it will also take away that gritty trigger feeling. By placing the .010 plate on the sear ramp between the sear and the sear ramp it will reduce the travel regardless if you remove, add, or leave alone any of the springs. It's a very easy mod to do and is completely reversable if you ever need to send the gun in to S&W.....

[tonytgman]

Ok, the heck with trying to sale the kit. This is what I did to my sw40ve. To lighten trigger pull, First - I took a ball point pen spring and cut it a little shorter then the original trigger return spring and bent the ends to resemble the oringinal spring and put the trigger assembly back together. Second - I took the sear assembly apart and completely removed the outter spring of the two sear springs. Third - I polished the back of the sear ( the part that contacts the the sear ramp ) then reassembled. Now that we have lightened the trigger pull, it's time to shorten the travel. Go buy a set of filler gauges ( can be bought at any auto parts store ) starting at .006 on up, and a pair of tin snipps, you will also need a dremel for sanding and polishing purposses. Now measure the sear ramp and cut the filler gauge to fit the entire portion of the sear ramps length ( from where the ramp begins to curve up all the way to the end of the ramp )even though the sear does not ride on the entire length of the ramp, this is neccessary to keep it in place ( I started with .006 and worked my way up to .010, I recommand starting with .006 and work your way up for practice and personal preference ). You may need to cut and assemble a few times to figure a good length. Once you have the proper size ( length and width ) cut out, use the dremel to sand and smooth the edges. At the edge that the sear will contact first needs to be sanded like a ramp or angled for smooth transition with the sear. Now, polish all the edges and even the flat part that will contact the sear, clean, use a little grease between the sear and the new ramp, slide the new ramp forward for better reassembly, then reassemble the gun. Once the gun is reassembled squeeze the trigger softly to full pull to make sure the new piece is in it's proper place. And thats pretty much it, although you may need to polish more if you get any gritty trigger pull. Like I said I worked my way up to .010 and it works great, reduced a lot of my trigger pull to around half the amount of pull. DO NOT CHANGE YOUR STRIKER SPRING !!!!! It is neccessary because reducing your trigger travel also reduces the amount of striker travel... I do not recommand however going any further then .010 I tried .011 and .012 and had problems with the sear engaging the striker, but you may find that more, or even less works better for you. BTW this mod will also prevent wear on your original sear ramp. Try it and post to let me know how this all works for you. I will also try to work on getting pictures of this procedure for anyone who needs them...

[TNDixieGirl]

So now we have two active threads regarding screwing up the only safety feature the Sigma has?? Why?

[tonytgman]

TNDixieGirl;
The trigger is not the only safety the sigma has. There is a striker safety as well. If the trigger is not pulled the gun can not fire due to the striker block which blocks the striker from coming into contact with the primer of a live round, the trigger must be pulled !!! Besides reducing the amount of trigger pull and lightening the pull does not eleminate the safety, it actually increases accuracy by eleminating the jerkiness and the wondering when the damn thing is going to fire. Also we all just like to tinker with them to see if we can improve on our sigmas.....

[TNDixieGirl]

Although I do firmly believe that by reducing the trigger pull you are also reducing the safety of the gun, and nothing will change my mind on that, my bigger question was why a new thread was started about it when there's still an 8+ page thread that is currently discussing the issue? It's just seems a little redundant.

Tinker on.

[tonytgman]

TNDixieGirl;
I do agree with you on the fact that it is redundant on starting a new thread on the same subject, however I disagree about the safety issue..... But to each his ( or her ) own.....

[hodadd]

Redundant, yes. Welcome to the internet. Most of these gun forums are redundant to some degree or another. I started a new thread to share my personal observations and efforts to improve what is otherwise a fine pistol. I would have posted my part on another thread if there was a definitive Sigma trigger thread, but since there was not; I started my own.

As to those naysayers about degrading a safety feature. Some modification will certainly do that, others will not. Lightening an otherwise absurd trigger pull will not affect the safety of the weapon. Hence, all those gunsmiths around the country who earn a decent honest living doing just that. In fact, I maintain that intelligently lightening the trigger pull can enhance the safety of the pistol by increasing accuracy. But, hey, to each their own.

Also bear in mind, the Sigma is produced under difficult legal conditions for S&W Inc. They are under an out of court settlement with Gaston and his buddies, which is confidential and is rumored to include paying money to Gaston for each pistol sold. It also rumored to include a mandate that the trigger be the way it is, crummy. This court settlement is one of the reasons S&W is letting this line languish and is pouring their efforts into the M&P.

[tonytgman]

hodadd;
I was not trying to put you down or anything by saying this thread was redundant it's just that there is already a thread on the subject, but as far as the other stuff you said in your last post all I can say is Yeah you go boy I'm with you !!!!!

[hodadd]

Hey no problem-o tony. No offense taken. I was just kinda continuing the dialog.



Well, I took it to the range and tried it with a mixed bag of ammo; including military issue ball ammo. And, all I can is: I'm happy. It worked perfectly.

Now I will do some smoothing and polishing to finish up the gun, but otherwise I'm completely satisfied.

I know I could go lighter with a lighter return spring, but for me this just about right. I'm very pleased.

[tonytgman]

Hey hodadd;
Did you try my mod's. And if so how are they working out for you?????

[hodadd]

Originally posted by tonytgman:
Hey hodadd;
Did you try my mod's. And if so how are they working out for you?????

No. I did my own thing.

[tonytgman]

hodadd;
You should try adding the new sear ramp plate ( one of my mod's ) which I had explained in my earlier post. If you like the gun now you will love it after you do this particular mod..... After doing it to mine it made the gun go bang right when I wanted it to do ( towards the begining of the trigger pull ). Just try it I swear you'll love it.....

[tonytgman]

I really wish I had enough materials to make all of you this new sear plate so you all could enjoy the great feeling of this trigger mod..........

[hodadd]

I actually don't mind the long pull. I just want it clean with a crisp break, which is what I've got. I might try your suggestion down the road, but for now I've achieved my goal of a lighter pull while being close to factory original.

[Walthernut]

Rather than start another Sigma thread I have a 40GVE and I sent it back to S&W for a trigger problem. They received it at the factory on Jan 13 and I got a work order letter on Jan 17.

[Mickstix]

What was your trigger problem? Or did ya just tell em it didnt feel right? (I've read that's all ya need to tell em, and they'll do "something" to the trigger to smooth and lighten it?) Let us know how it feels when ya get it back!! Im sure there are a lot interested!! Especially if they can smooth out a VE series trigger with the stock springs and stuff!

[Walthernut]

I got my Sigma 40GVE back today. My complaint was trigger recovery.
They performed the following:
Barrel modification
Adjusted trigger pull
Replaced sear housing blk assy
It is 200% better on the trigger pull and I'm going to keep it.
A twelve year old would have no problem with the pull and it's the smoothest DA I've ever had.
THANKS S&W

[meme]

Originally posted by tonytgman:
I really wish I had enough materials to make all of you this new sear plate so you all could enjoy the great feeling of this trigger mod..........

I believe you have pictures of your mod. Could you send them to me? I'm having a little trouble visualizing. Send to [email protected]

Thanks

[tonytgman]

meme;
The e-mail has been sent to you. Just follow the instructions I've sent you, check out the pic's and it should help you to better your weapon.
Thanks for your interest.....

..........tonytgman..........

[Mickstix]

Bump!!

[tonytgman]

Bump !!! Back atchya !!!

[Deltaboy]

Originally posted by Walthernut:
I got my Sigma 40GVE back today. My complaint was trigger recovery.
They performed the following:
Barrel modification
Adjusted trigger pull
Replaced sear housing blk assy
It is 200% better on the trigger pull and I'm going to keep it.
A twelve year old would have no problem with the pull and it's the smoothest DA I've ever had.
THANKS S&W

I sent my Sigma 40VE back to Smith and Wesson service center and a phone call and a written note that the Trigger was too heavey and gritty and it was not up to S&W standards. They covered the total cost of shipping and handeling along with fixing the Trigger. This is what a S&W trigger should always feel like.