Well, 45acp+p is a definite step down from 41mag, and you are giving up even more performance with a shorter effective barrel (different barrel measuring techniques between revolvers and semis).
Here is how that round acts at different barrel lengths.
Ballistics by the inch
a 6" barrel looks like what you need to get advertised performance.
all that said, you should have enough round there to drop a deer with good hit placement. Just don't shoot beyond your ability. Good luck and have fun this fall.