Personally I would not use 45 ACP for this purpose. However if I had to, I think I would go with a 230gr XTP over a very stout charge of Unique. My testing with max loads of this powder gave me 930fps average out of a 5" bbl. A Gold Dot gave the same velocity. 440 ft/lbs of energy with a 45 caliber frontal area is nothing to sneeze at. If you do work some loads with XTPs or Gold Dots, keep in mind that both of these bullets require a shorter COAL than FMJ ball for proper chambering. This will reduce remaining case capacity.

Also, as much as I don't want to say it, I think a Glock 21 would make a better "deer gun" than a 1911. The G21 is an extremely strong firearm, derived from the G20 10mm design, firing the low pressure 45 auto. While this is not a license to work up dangerously high-pressure loads, it does give you some leeway to stretch the cartridge's legs into the "+P" range.