The .45ACP in a revolver has its place- using 1/2 moon clips isn't all that hard with practice and is pretty fast for reloads. The main reason why they are still made is for concealed revolvers- you get big bore performance out of a small easy to conceal revolver.

Like otehrs said, 44magnum, 45 Colt, or 454 Casull would be much better choices for deer hunting. There are others that have come out lately, but the ammo is tougher to find and they don't really offer any greater performance.