RE: .44 magnum rifle
From all the numbers I have seen a modern slug gun or inline ML would be better than a 44 carbine. Not that it won't work, especially at 50 yards. If you want to use it I say go for it if you don't mind limiting your range. Sounds like it might be fun.
Myself I would take the .270, but that is just the kind of guy I am.
Paul