+First SG2K Upgrade

i ordered the following from MCarbo: Optic mount; Recoiless charging handle; Buffer tube cover; Red buffer; Muzzle brake; Quick deployment latch; single point sling mount; and Angled front grip. They all arrived quickly and I just completed installing all of them. I must say that the installation videos & printed instructions were spot on. However, it took me much longer to install some of them than the video showed, but doing this for the first time it is understandable. Installation went smoothly for each item. I had dreaded installing the locking pin on the recoil spring, but I “double compressed” it with my wife’s help and exposed about 3/4 inch of the wire without having to hold it there with my hand and it went on without any problem. I took it out and ran a 17-round mag through it without a hitch. At 35 yards from a rest bowling pins and freon tanks didn’t stand a chance. All left to do now is to purchase a foam-lined case and fit it, along with four 33-round stick & one 50-round drum magazine in it. Thanks to MCARBO for some cool upgrades & help with this.


I had the same experience. Go ahead and get the trigger kit. Watch Chris’s video three or four times then watch/pause while you do everything. Easy peezy. Makes a HUGE difference. Now I have a completely (translated: much better) gun than the one I purchased. M*Carbo is the best.


I bought the parts/pins/etc kit, but opted for the Kel-Tec install - right now I don’t have a good place to work on stuff. I also got a Red Lion front sight (look into that), and Kel-Tec installed that along with the MC stuff no extra charge. I was really afraid of tweaking the barrel trying to unscrew the original front sight. They made sure it was indexed correctly and that the proper amount of threads were showing. I think the KT front sight is the worst part of the design, and the Red Lion sight is slick. They also made sure to return all of the original parts.

I had already gotten the MC rear sight, so I could control its up and down. Bonus is, the peephole is better than the original. I love their attention to detail from a user point of view. I also put on the extended bolt charging handle (the long one, not a fat one).

While Kel-Tec had the S2K, they found a problem with it, which didn’t affect the function, so I never would have noticed it. However, they did, and fixed it, and were smart enough to put in a note explaining what was what.


That makes me feel better. I sent my S2K in for many mods, getting the old parts back is good as backups if needed. Did they also send the materials like polishing compouns etc back? Hope so or i will have to order some. How long did it take?

Thanks. I plan to send mine in for the completion of the M*CARBO upgrade. Looking forward to running many, many rounds through it.

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