.45 Colt wouldn't be my first choice for deer, but it should work. I have a 26" Marlin Cowboy in .45 Colt. It's been slicked up for CAS and I had shot it with reduced loads. The heavy walled brass won't seal against the chamber walls with a low powered load, causing blow back. I got tired of that and got something else for CAS. I loaded 300 gr. lead and jacketed bullets with max charges of 4227 and there is absolutely no blowback with those loads. I think the MV is around 1,500 fps., although I've never clocked them.
There have been a bunch of deer killed over the years with .38-40 and .44-40 rifles, neither of which churns out the power of this load. I would think the .45 Colt would be a potent deer caliber out to around 150 yds. I'd want something else for longer range shooting.
IMHO,
DF
