has one for the .30 AK ya know. So there's your chamber-insert. The Army had a .22 unit(for M16 which worked by means of stuffing a .22 mag box down inside a 223 mag box. So it's obvious that such is quite feasible with the internal mag of the sks, too. Just a question of having it sit a bit "higher' in the gun, which is easy to arrange(by having a flange on the top of the .22 unit mag overhang the sides of the sks mag) Such a unit would make the sks about twice as desirable a shtf choice as it is without one. Problem is that a .30 AK suppressor has such a large ID hole that it might not suppress the .22 unit much. Dunno. The .30 AK can would have to be fairly large, and you can make up for not having a "tight" fit between bullet and the tunnel thru the baffle stack, by having a large enough can.