Never took a deer with it (illegal for Indiana), but for what its worth, I loaded a Lee 255gr swc in an ACP case with a "+p" charge of HS6 that netted me 850fps out of my 1911 with no issues whatsoever. Shot through 6" tree trunks just fine, should slide right through a deer. Only 50-100fps slower than the original 45 colt load.

If I were hunting with a 45acp, I wouldn't be worried about expansion, I'd just want to make sure I had two holes for the price of one.