If you like the 1911 enough to try it on deer, there's a better way to boost the power. Get a longer barrel, and then tinker with powder types and charges.
I've given this a lot of thought for a few years, but so far, I've stayed with my wonderful Remington 11-87 and bulldozer 12 ga. slug loads. In Ohio, we can use handguns, but caliber must be .38 or over, minimum 5" barrel, and no bottle neck cartridges. So I bought a 6" drop-in 1911 barrel. In a handgun, each additional inch gives you the chance to boost velocity considerably.
But there's something even better, and legal. Numrich's is still selling a kit to make the 1911 a legal detachable shoulder stock carbine. You get a mainspring housing slotted to take a stock, plus the stock, plus a 16 1/4" barrel. It sounds awkward, but the thing is a tack driver. All is legally well, as long as you do not use the stock with a short barrel installed. You could use the long barrel without the stock, as a legal deer hunting handgun in Ohio. All you need are good sights, such as a red dot.
With registered Thompsons (10" standard barrel) we can get around 1000 FPS with standard .45 ACP ball ammo. Load it with slower burning powder and you can get well above that. So for a handloader who likes to hunt with a pistol, there is no reason why you cannot use a long slide 1911, or one with just a longer barrel, and boost velocity to the 1000+ FPS range, where a well made expanding bullet can do a very respectable and accurate job on deer in the 50 to 75 yard range. I've never had a longer shot here in Ohio, and most are much closer. No thoughtful hunter should consider taking a pistol shot at a deer beyond 75 yards anyway.
Maybe this year I'll try a handgun. I keep thinking about my .44 Automag. Then I think about that rifled and scoped 11-87 and the certainty of it, and I hesitate.
That gigantic air rifle sabot slug does the job every time...all the way through, and with an impressive exit hole.
