BRL: Go on up to the 45 ACP/1911 Forum and view the discussion on Hunting Deer with a 45 ACP - there is some interesting information there that might help you. In addition, there are some hardcast bullets by Beartooth (good sized metplat) referenced in that thread that may be of further interest to you as they are heavy slugs for the ACP but clock out at a fairly good clip.
Also, there is discussion of the 300 gn jacketed rebated bullet by Northwest Custom Projectile that attained excellent accuracy in testing and incredible penetration. They didn't shoot all that well for me but my testing was limited. These folks also produce a 260 gn slug in the same configuration which you really have to view to see what a rebated bullet for the 45 acp looks like. It's pretty interesting. I purchased some of the 300 gn slugs and even seated them backward as the profile of the slug was incredible when seated that way. They were no more accurate for me than when they were seated properly but hay, they shoot better in some guns than others. The 300 gn slugs also penetrated a bunch more than the standard ball slug.
I think I'm going to try some of their 260 gn slugs, both forward and backward (lolol) to see if they are any more accurate than their 300 grainers were in my pistol.
Mind ya now, I'm not recommending the acp for whitetail even though I have taken one at fairly close range with an older load but I would think that a 250-260 gn slug at 850-900'/sec (attainable in the acp) should do the job at reasonable ranges. HTH. Mikey.