[soundguy]

apparrently thay are big guns.. like 35+??mm

and the inserts look like a big aluminum slug with a central hole. i have seen 22lr and one ofhter caliber listed so far.

there was a warning that installing the insert constituted making a firearm, so 'check your local laws' etc.

someone is making these inserts comercially.. I'd imagine that means for liability reasons.. the insert itself must be able to withstand the chamber pressure of the cartridge without respect to the? 50-70 yr old gun?

then again.. I'm asking because I don't know the skinny on them either?