Well I guess i'll join the S12 discussion also. My S12 was converted by me and I followed the tutorials, pics, and, explanations on the Saiga 12 forum on how to do that and how to polish the bolt. Mine is a 3 port gun with ports approx. .063". I test fired it before the conversion to make sure it functioned before I converted it. The shells I have fired throughout all of my testing are: Winchester Super X 2&3/4 #8, 3&1/4 DR EQ, 1&1/8 oz shot - Remington Field Load 2&3/4 #8, 3&1/4 DR EQ, 1oz shot - Winchester Super X 00Buck 12 pellet unplated - Winchester Super X Rifle Slug HP, 2&3/4, 1oz DR EQ . The S12 has: KVar buttstock and pistol grip, Tromix DIY trigger guard, Tromix Tapco modified fcg, Krebs front and rear sights, MD Arms VPlug, MD Arms flash hider. Tangodown VFG, Streamlight PolyTac HD LED and the "Pauly's STEELIN' " bolt, bolt carrier, fire control group modification. This included; a mirror polish (and correct profile on the bolt), the locking lugs, bottom of the carrier, rail guides, recoil spring channel, all friction bearing parts on the FCG (including the axis pin), tuned the extractor, and media blasted the carrier to give it a more matt finish. When I polished my bolt it was my first time and I did a very basic (read, a little rough) contouring and polishing. I also slightly smoothed up the rail guides on the carrier. I knew that it was not "finished" but it was where I stopped. When I saw the " back burner special" price of $40.00 shipped I contacted Paul. For all that would be done plus the advantage of having an experienced person see the rough contouring and polishing that I did and give a professional critique of it would be worth it. Paul did an outstanding job on all of the parts including correcting my errors and I received them back four days after he received them. I could immediately tell a difference when I put everything back together, the action was considerably smoother than before. Aesthetically speaking the carrier looks a lot better with a more subdued matt finish. I took the S12 out back and put several rounds of the above mentioned ammo through it. Everything functioned perfectly and very smoothly, no feeding issues at all (w/ proper V Plug settings). I think that the only thing left to do is to open up my 3 ports to the correct factory specs. Remington will only function on the V Plug #5 setting - hulls land about 5' @ 2 o'clock. Winchester #8 same results as the Remington. Winchester slugs will function on setting #3 - hulls drop out about 18" @ 2 o'clock. Slugs on Setting #4 - hulls land about 5' out @ 2 o'clock. Same results with Winchester 00 Buck on settings #3 and #4. So far my S12 has been flawless with everything I have put through it. Got an MD Arms 20 rnd drum, One SGM 8 rnd stick mag, and 3 5 rnd mags. Now i'm just waiting foe MD Arms to release their double stack mags. Carrier work done by Pauly's STEELIN'