A word of advice about hot powder +P loads in your 9 x 19 handgun: some handguns are not built for +P loads (consult your user's manual for your handgun).
With handgun loads your hollowpoint will not expand about 50% of the time. This is what they have found in numerous shootings where handguns have been used as handgun bullet velocites are so low.
Go to the website below and read the information there for more information on handgun stopping power.
http://www.firearmstactical.com/hwfe.htm
Second as far as expansion goes what you say is true. That is why every one of my posts specifies a MODERN +P or +P+ hollow point. The modern bullets do expand reliably even when fired through multiple layers of denim or leather.
Third as far as wounding characteristics go, it is all fine and good that he can write a scholarly article. Fackler also does a good job of running his mouth and produces articles and equations that show that a 45 ball round is more effective than a modern 9mm hollowpoint. (For that matter his equations have shown that 124 or 147 gr 9mm Nato ball are both much more effective than a modern 115gr 9mm hollow point) Both are manifestly bull$#!T.
If you want real wounding characteristics go to the actual shootings. The actual shootings show a different reality.
The modern 230 gr 45 hollow point is an excellent round but it is only slightly more effective than a modern 9mm hollow point in ACTUAL shootings. The actual shootings are what counts.
You can post these articles until you are blue in the face. I love Jeff Cooper more than the next guy and his opinions were correct WHEN he formed them. Now they are patently WRONG. Technology has marched on and is producing more effective rounds every year. BTW the MODERN 45 rounds are looking more and more like 9mm in their loadings (though I would carry the 230 if I carried my 45).
Amend Fackler to say Hatcher