http://www.hipowersandhandguns.com/9mm%20vs%2045.htm
Read the whole article, it's pretty interesting, I think, and the man has obviously "been there, done that" with regards to shooting lots of animals with zippy .355's and slow .45's.
What I personally drew from it:
We know the 9mm and the .45 do NOT create identical permanent wound-cavities. The .45 creates a larger one. Yet the 9mm performed just the same as the .45. Why? Velocity? TC made up for the smaller permanent cavity? I won't even pretend to know. However, these experiences also seem to discount BPW having any effect, at least that this author saw. If a lightweight animal being hit with a zippy round reacted the same as a lightweight animal being hit with a 900fps hard cast bullet, I would say BPW was not at play here.
Included is a picture of a wound from a .45 and from a 127 +P+. Sadly, they are close-ups and you can't tell much.
Again, from the article:
I don't think this means they did BETTER than the .45, but that they did as well (reading the whole article), and he could not account for it. However, I would hazard a guess that the damage he referred to these rounds causing was a factor of fragmentation and not necessarily velocity. Ergo, chalk it up to bullet design instead of velocity (I guess you could argue that velocity caused fragmentation, but then, one could just argue in favor of using Glasers or something, not something I would do.). As he said later in the article, a 185gr Corbon did the same thing.
IN THE END
It seems that regardless of the mechanism used, 9mm, .45, .40, and .357 SIG all do about the same darn thing when you use the right ammo. You pays your moneys, you makes your choice, and you do your damndest to defend it on some random internet forum.