There has been much talk and conjecture about the S&W Sigma. I set out to create a test. Tomorrow, on April 23, I am going to head out to the range with a Sigma and 1k of the dirtiest ammo possible--Wolf 9mm.
The Sigma is very inexpensive, which is what causes many people to gravitate towards it. A local shop is having a sale on them, the price is $250 and includes (4) standard capacity (16 round) magazines. Because the price point is so attractive, I decided to do a test on this platform.
First, IllicitDreams brought his Sigma to my house. It has had approximately 400 rounds through it so no break-in issues should occur. We broke the gun down and I cleaned--but did not lubricate--the parts. I was surprised (although I shouldn't have) at what I found inside. The slide assembly is almost exactly the same as a Glock. This shouldn't be surprising since Glock sued S&W (and won) a few years back for patent infringement. Here's a quick breakdown of the gun:
Look familiar? Well, if your a Glock owner it should. I did not break down the trigger assembly because I am not familiar with the setup (and it isn't my gun) but the slide assembly is almost exactly like a Glocks.
Inside view of the lower:
While stripping the slide, a part of the gun (all plastic pieces are white on the Sigma as opposed to the black on the Glock) a piece of the striker assembly shot out across my basement someplace. After more than a half hour of looking with no success, I actually broke down one of my Glocks and the Glock part fit in perfectly. Of course, as soon as I had the slide assembled we found the original parts and I replaced them. So yeah--the Sigma has all S&W parts inside of it now.
Due to this parts issue, IllicitDreams and I sat down and compared each part of the slide assembly against each other. Here are the results:
(All images have the Glock parts on top and the Sigma parts on the bottom)
As you can see, the plungers are slightly different--perhaps not similar enough to be interchanged.
Same with these parts
Extractors are noticeably different--the Glock extractor is too wide to fit into the Sigma
Yes, the Glock guide rod looks larger--this is because that is a G34 guide rod. When I used my G19 guide rod, it fit right into the Sigma.
The plunger springs appear to be the same.
Striker pins are slightly different. Notice the spring on the Sigma spring to avoid an extruded firing pin. Frankly I find this to be a non-issue in Glocks. Perhaps a slight change to fight patent infringement?
The Sigma part is slightly longer than the Glock.
The striker spring on the Sigma is smaller and stiffer whereas the Glock spring is longer and less stiff. Actually, the Sigma spring is much harder to use than the Glock spring when installing the retainers (hence the problem we had installing them). I think these would be interchangeable though.
Slide comparison between my G34 (obviously not cleaned) and a Sigma.
The slides were so similar, we decided to do a test:
the slide did not lock into place, although it fit onto the frame. The Sigma frame is slightly longer. When we tried to put a Sigma slide on a Glock frame it didn't work because the Glock ejector is in a different location.
The front sight appeared to be staked in place and also glued with some kind of polymer. Looked a bit off:
The Sigma also has some marks left over from plastic injection molding that the Glock does not. This is most noticeable on the trigger.
I weighed the trigger in at a very spongey 11lbs(!) No excuse for a trigger that heavy IMHO. I also do not like the non-standard rail on the frame of the Sigma.
Anywho, tomorrow I attempt to put 1k of rounds through her. Lots of pics will be taken and I'll update this thread after my range trip tomorrow.