Pictures Of Sigma Internals?

[Kawabuggy]

Sultan,
There is NOTHING inside the slide that needs to be polished! The firing pin guide is inside there and is made of plastic. The only reason you want to remove that slide cover is to get to the striker spring----Midway part #295637 "Wolff Striker Spring S&W Sigma 3-1/2 lb. reduced power". THIS is what will reduce the trigger pull-NOT POLISHING.

The parts you want to polish are the sear contact points with striker, sear pin cavity, striker head, and sides of sear pin body where they ride in the sear bracket. All of these items are contained in the grip body.

When you are ready to replace the striker spring, you will have to remove the plastic slide cover. My honest recommendation would be to purchase a new slide cover from Midway at the time you purchase the striker spring. They are not that expensive-AND YOU WILL DAMAGE/MARR the original one getting it out. I did minimal damage to mine getting it out. Just understand that you will have to put a screw driver between the slide and the cap and then work it down slowly. Understand that there is a great amount of spring pressure on the cap and that you must be ready to catch the ejector spring & rod when the cap finally breaks loose. The ejector spring and rod will come out with great force and you can lose them if you are not prepared to catch them with something. I put a rag over the cap and only expose the gap that I need to get the screw driver into. What I did was wrap a towel around the slide, and then put it in a vise to hold the slide while I pried the cap down and out.

If you have any other questions, post away.

 

[Sultan]

I see where I got confused. You are using Midway part numbers and I'm looking on the Wolff site. So sorry for that, I have it straight now.

I read another post on another site where the fix applied was to very lightly sand the bottom of the housing block where is contacts the sear, then polish it as you have suggested. Your explainations are great, by the way.

Everyone else is pretty much suggesting to dry fire/range fire the heck out of it to get the trigger to loosen up. It seems that by changing the spring and polishing - possibly some light sanding, we are doing the same thing as firing the heck out of it would do. Personally, I want the weapon to be comfortable to shoot right off and I'm like you, Kawabuggy, I like tinkering and doing the work.

I did want to ask Mustang about taking the length off the pigtail spring. Could you explain that process in a bit more detail? Did you straighten out the clipped end when you were done?

Is there a chance of getting any picture of any of this? Thanks.

 

[Kawabuggy]

I removed my pig-tail spring entirely.

I also removed the outter sear spring.

I'm not sure I would sand any material off the sear ramp. The reason I would not touch that plastic ramp is that it would be too easy to get carried away and remove too much material. That could alter the timing of the hammer/striker release. Any sanding that you do to the ramp where the sear touches it, will result in a longer trigger pull before striker release If you just wanted to lightly touch it though I would use 1500 wet sand paper and just lightly go over it. That would certainly smooth out any minor surface imperfections. Caution is the key there.

I did not take any pictures while I was doing the work. Had it apart last night cleaning it, but did not think to take any pictures.

If you need help with anything specific, just post back here. I get an e-mail each time someone replies and I can check it.

 

[99Mustang]

Sultan,

Put a cutoff wheel on the dremel and spinning at it's lowest speed touch one end of the pigtail spring to the FLAT SIDE of the cutoff wheel. Do NOT use the edge of the wheel as it's too wide for the springs and you can't control it well. You're basically shaving off the spring material. Don't hold the spring on the wheel too long, tocuh it for a second or two at a time. You want to remove only a little material at a time. It takes 2 - 3 minutes to do it right. Keep the spring perpindicular to the wheel, so the end of the spring remains flat; if you do this you won't have to straigthen the spring at all when done. I held the spring with needle nose, keeping a very gentle grip on the spring (too much and you may bend the spring). Again, make sure you have eye protection as pieces of the spring will fly off.

I took about 1/8" off both the pigtail and the outer spring.

I'll see about taking pictures if people are interested.

Kawa,

I didn't touch any plastic pieces for the same reason you mentioned. All the surfaces on the plastic where smooth, so I saw no need to modify. Besides the trigger work, I also polished the metal contact surfaces on the slide and frame, just enough to remove the matte finish, this helped to smooth out the movement of the slide when racking the gun.

 

[plastikguy]

very interested in see pictures

 

[Sultan]

I'll take some pictures this weekend and post them. I'm going back into the sear section to polish some more.

Mustang, I'm sorry to be so dense, but I still don't understand if I'm actuall shaving a coil off the pigtail spring, talking some of the tail off or removing material off the length of the tail. I would appreciate one more clarification on that.

Does anyone know what this pigtail spring actually does in the weapon? I have mine out and everything works properly, but I'd still like to know it's purpose.

I'm pretty convinced that the outer sear spring is really just there to hold the inner spring in place. It may be that taking an eighth-inch off it would do the trick.

Kawabuggy, that's a good suggestion to get another slide cover before changing out the striker spring. I'm getting at least one - I think they are $5 or so.

I'll try to have those pictures posted on Monday.

 

[99Mustang]

Plasticguy & Sultan,

See my post in the S&W-Smithing section. I posted several pictures of the sear housing assembly and what I did to smooth and lighten the trigger. The work was done on a 9VE, but I suspect it's the same for the 40.
Sigma trigger work (pictures)

FYI, I've shot 700 rounds through it since the trigger job and not one FTF, FTE.

 

[Sultan]

99Mustang,

Yes, it is exactly the same for the 40VE. Great pictures, too. Thank you for sending us the link to that. It appears from the pictures that you didn't do anything to the coiled (pigtail) spring at the bottom of the sear assembly, that you only took material off the inner and outer sear springs. Is this right?

Thanks again.

 

[99Mustang]

Sultan,

I left the small lower spring alone, it does not contribute much to the trigger pull. It resets the trigger sear to it's rest position and I didn't want to make any changes there. I did not want to reduce reliability.

 

[Sultan]

Thanks for all the great information here, especially to 99Mustang and Kawabuggy. I think I'm ready to tackle my Sigma trigger job now armed with really good information (and excellent pictures).

I'm in the process of finding the Dremel polishing kit that has the long thin polishing attachments in it. By the way, there is an excellent metal polish called Metal-Glo that will put a mirror shine on any metal. It's made for show knife polishing, but I've found it works really well on the parts of the Sigma I want to polish and it doesn't remove material that I can tell. It sells for about $5 a tube.

 

[Kawabuggy]

I completely removed that small spring that is wrapped around the lower sear pin and have not experienced any ill effects..... Yet.

In regards to polishing, I started with 800 grit paper, wrapped around a flat piece of plastic so that I was certain I was not introducing divots from uneven sanding points. Very light polishing with 800, then quickly moved to 1000, then final polishing with 1500 wet sand. You can get all of the sand paper at most any local Pep Boys, O'Reilly, Auto-Zone, Kragens, or the like.

 

[Sultan]

I finished phase one of the Sigma trigger rework this weekend and it makes a huge difference in the smoothness and the toughness of the trigger pull.

I followed 99Mustang's route and shortened the outer and inner sear springs by 1/8 inch. I left the coil spring installed at this time at the bottom of the sear assembly. I also followed Kawabuggy's advice and polished the heck out of all the sear parts. I found the Dremel Polishing kit ($20) to be a huge help because it comes with red polishing compound and great polishing attachments. I hit all the parts with 800 grit sandpaper lightly and then turned the red coumpund loose on them. I finished up with the Metal-Glo polishing paste and now everything looks like mirror finished steel. I also polished the top of the trigger lever and the slot in the trigger lever where the sear mates to it.

Now the trigger action is about half as hard as it originally was and it is glass smooth all the way through. Also, there is no more loading at the end of the trigger pull when it was stock. I also took this opportunity to polish the cartridge ramps that are cast into the breech end of the barrel assembly. Mine were really rough and very unfinished. They look like mirrors now and are totally smooth.

I'm going to shoot it like this for a while before I decide whether to change out the striker spring or not.

 

[EPWrangler]

Instead of the 3.5 lb Sigma striker spring I used the 4lb glock. It fits fine and works very well. I also removed the outer sear spring and the little pigtail spring below. Everything works just fine.The polishing of the striker and sear engagemnet faces does help smooth out the pull.

 

[mr.72]

I just got a new 9VE and we have run about 300 or so rounds through it, with the only failures on feeding with low-pressure (cheap) ammo. Last night I took it apart and removed the "pigtail" spring and the outer sear spring and I was considering testing it this weekend. However after reading the various threads on this topic I have noticed this alarming trend of these mods causing the gun to have a FTF rate of about 1 in 150 or 200 rounds and this is totally unacceptable to me so I'll be reversing these mods and returning it to stock.

 

[Sultan]

I've studied the design of this assembly for quite a while now. I think the outer sear spring is actually there to hold the inner sear spring in place. If you ever take them out, you'll find that the inner spring has a lot of tension on it and it tends to bow without the outer spring around it as a guide. This is why I opted to use Mustang's method of shorting a small amount off the springs and it worked very well in reducing the amount of trigger pull effort. As for the pigtail spring, I know it makes the sear stand back in position, but why it has to be such a strong spring is beyond me, and I know springs pretty well.

I have to admit that I had mine out and then after reading the threads, put mine back in as well. I think the FTFs are mainly caused by using that 3.5 lb Striker Spring mod, but EPWrangler's find on the Glock spring has me hunting for one of that strength. I still may take the pigtail spring out and test the gun for a while before I write that one off.

I did want to pass on one bit of discovery about the Sigma that I learned the last outing at the range. I started the session out slowly squeezing the trigger and let me tell you, it was a pain even with my trigger/sear mod. I discovered quite by accident that if I squeezed the trigger very quickly (more of a controlled pull), the session became really fun and I was still hitting the target accurately. So with Mustang's trigger mod and experimenting with the WAY I squeeze the trigger, this gun is starting to get really fun to shoot.

 

[mr.72]

OK, Mr Sultan, let me see if I concur with your assessment.

The outer sear spring is actually a much higher-rate spring than the inner sear spring. The outer spring is not under as much preload as the inner spring. The preload of the inner spring causes it to require a certain amount of static force to begin compressing it (equivalent to the pre-load force), but then it is linear beyond that point (basic spring theory not regarding their use in a gun). So it appears that the use of two springs with different rates and different preload amounts is there to give more of a progressive rate, where you have to pull with x number of lb in order to move it at all, then beyond a certain amount it becomes linear with a curve at the beginning. However it seems certain that the outer spring is most of the spring rate, and the inner spring exists either to keep the outer spring centered, or to provide some pre-load initial force, or (likely) both.

The pigtail spring is very strong because it has very little deflection. It only moves a small amount. There is a lot of leverage on it.

If you cut down the sear springs then you remove the preload. The dynamic force required to move the trigger is the same, it's just the initial force required to get it moving that changes by changing the preload. I do think that is a valid concern. However I bet part of the reason there is so much preload on the inner spring is so that it does not come off even under harsh impact. I don't know where those springs could go if they were to try to slip out of the seat but it couldn't be good for them to get crunched in the sear assy.

Regarding squeezing quickly, I noticed that if I just went "bam-bam-bam" and fired quickly that my accuracy was very good. Maybe a 2" group at 7 yards (way better than my accuracy when firing a single shot and waiting). So you may be onto something. Pull all the way when you are ready to fire. No progressive pull. My wife discovered the same thing. Pull hard and fast, you shoot this gun better. I think that's an accurate simulation of defensive firing anyway, so it makes sense.

I had a suspicion that the trigger tension was affecting my accuracy but now I do not think it is. I can dry fire it and keep the sight right on the target with no movement. I don't think it's the trigger that's pulling my groups down and to the right. I might just need to adjust the sights.

 

[mr.72]

by the way, cutting those springs, if you cut off any more than the "dead" coil, will not only reduce preload but it will increase the spring rate (thus increasing the dynamic trigger tension).

 

[Sultan]

The way the inner spring is made, if you don't take off more than 1/8 of an inch, it still seats properly in the sear parts and the outer spring still rests properly, too. My springs have been ground down, not cut. Cutting will damage the springs - grind with care so as not to heat the springs. It's up to you if you want to try any of this. Apparently, you are not happy with my explaination of the springs. Make your own decisions, I'm just reporting what I've found out from use. The trigger pull all the way through from rest to firing is much lighter, not just the preload.

I had an instructor at the range tell me that holding my head more erect during firing would change the way my round hit the target. I've always been a rifle shooter, so I'm used to holding my head snuggled down into the stock. I tried what he said and my down and to the right became bullseye. Couple that with the swifter squeeze and I'm having fun with a gun I was about to get rid of.

 

[Kawabuggy]

I am still shooting away with my gun-with modifications-and have no problems to report. I felt comfortable enough with my gun to use it to certify for my CHL. Not a single FTF.

I have put another 300 rounds through it since I last posted. Initially when I first made the changes I did experience some FTF's (2 in about 150 rounds) but those have since ceased entirely.

I hope everyone enjoys their new gun as much as I am enjoying mine. I got my rebate back, but am still waiting on the 2 free magazines.

 

[mr.72]

No point in getting defensive about it. My comments on spring rate and preload are easily verifiable since they are simply recitation of normal physics and are not related to gun performance.

One thing I did notice is that these springs load the pins in the little channel in the sear, so that whatever friction exists in this channel is exacerbated by high spring tension. I suspect this affects the feel substantially.

Mostly, for me, it is not a worthwhile tradeoff. I get better trigger feel and maybe better accuracy by an inch or two at 7 yards, and in exchange I void the warranty and potentially may reduce the reliability of a gun that is intended to be used almost strictly for self defense. Just not worth the risk. I can hit the bulls eye with the stock trigger. I can learn to do that repeatedly.