I'm very interested in this thread, as I just bought one myself! I don't have it in hand yet, but I'm also looking at options and possible mods for this platform. Please keep us posted on results from your testing of different ammo available.
Johninthecampers .375 pellets make a nice punch in rabbits,seen him crack one from 50ft away!Love my trapmaster,got mine from Tim with new seals and power mod.Excellant gun it is