A bolt-action would remove the need to fiddle with the gas.Yeah that would be kewl ! Would take a bolt with proper head and exrtactor and a barrel with proper feed ramps to take the presentation of cartridge from magazine. A metal lipped magazine could probably be done with careful plier work , A .454 would probably work the gas action OK, and the .45 Colt a manual feed . That would be the way to go ! Maybe I'll ask Paul Lietner-wise what he thinks !