Be very careful not to lose the inserts. They are not generally available. I have one of those Polish Tokarev "Sportowy" pistols that came with eight of the inserts. It also came with a recoil spring about half the length of a conventional one. I couldn't find any place in Canada or the US that had the inserts, and I wanted a couple more. They were made for the military as trainers, but obviously were a bad idea and after their introduction in the mid-fifties, quickly disappeared.
Then I found a man on Gunbroker who is Polish and sells a lot of mid-European gear, and I got ten of the inserts, unused. If you PM me, I'll give you what I can about contact information. Be really careful about not losing those things. I've read that the Poles also made a submachinegun that fired them. So there are apparently a lot somewhere in Poland, but that may be the only place. What a bizarre way to fire .22 cartridges in military guns.
