Those revolvers have no hop-up. Shoot a 500FPS BB without hop-up? Think about it

450-500FPS. No hop-up. Low range. You gonna call safety kill with that thing? Would it even be allowed on the field? (Chrono'ed guns at games around here are tested with a .2 bb)
Oh and btw, Tanaka, Marushin, and TM Python can take Green Gas just fine (It's primarily a danger to automatics because of the force against certain moving plastic parts). Might want to check what bb weight works best due to their fixed hop-ups.
"One does not care to acknowledge the mistakes of one's youth." - Quattro Bajeena aka Char Aznable