I worked with a guy who does the park pig depredation in this area and he trapped most of the hogs. We killed several with a .38 and a .45 cal pellet gun. They were Korean made and loaded with a scuba tank (something like 3200psi). Killed them quick but the guns were about the size of a Kreighoff trap shotgun and were about as loud. The velocity drops off dramatically with even short distances. With a special permit from fish & game we also killed many with a .22 LR but all of this was at a very close range and it was killing, not hunting. Also a lot of work.