Been working on this Vepr for about a month maybe. Started life as a 19" Vepr 12 with fixed stock. First cut barrel to 15" and threaded it. Didn't like the way it looked, said fuck it and cut it to 12 and threaded it. It currently has a Russian GK03 muzzle brake that looks a bit goofy but it works very well. 

Removed material and polished the bolt, bolt carrier and hammer face. 

Knocked the gas block off and reprofiled the inside of it. Drilled a 6th port and enlarged them all to 3/32. The gun right now really only likes 3 3/4 dram shells and some Wolf 00 buckshot. It tries to run the S&B 00 buckshot that MidwayUSA has on sale. I think it's the powder the S&B's use. It's very different when shooting them. I think some 3 1/4 drama would work now that I've put a lot of time into the gas ports and such. 

If I ever get to where I want to shoot the cheap Walmart shells I guess I'll have to move the gas block back a couple inches. Might be more than I can handle.

You will need to move the gas block back.

The gas system for the vepr is awesome at the factory length barrel. Very tolerant, but you mesed around with it a bit.

Liquidmetal would probably have info on it.

Nice csspecs mag.

If I can get 3 1/4 dram shells to run reliably without moving the gas block back then I'll be happy.