An argument that starts with a lie has no foundation in fact. Guns must be serialized (by regulation). A test identification bullet is on file (by regulation). The possession of automatic weapons is controlled (by regulation). Background checks exist (by regulation). I could go on and on, but I think I have made my point.
Test “ID” bullet? Several firearms I know of have a “test round” fired but not sure that it’s an “ID” bullet. Clarification someone? Beuhler-——?