since nobody's replied I'll add a little update.

the best of my understanding most of the Russian Sega and I'm sure that didn't come my spell right talk to text..
are interchangeable. the reviews I seen early on or not justified I do not believe this thing is absolutely awesome.

for the money I have and I am well pleased just another battle shotgun if it screws up throw it on the ground and keep going..
there are nice adapter kits to make it take the Sega mags I know once again it didn't spell it right.

adapters to make it take pistol grips AR type..
even adapters to make it use AR buttstocks and such..
you can even get rid of the front gas tube covers if you will I'm pretty much give it a quad rail.. has two position gas block the gas block fish reserve for heavy loads has run 1 oz loades at 1050 just fine granted ejection wasn't very far but they did function and work. two and three quarter inch buckshot loads at like 1350 recoil was very light.... a longevity will remain to be seen...