Ok, just to update my own thread, I have found some terrific data at ammolab that has answered my question as to what ammo I want! Here it is.... [url]www.ammolab.com/9mm_section1.htm[/url]. Check out the first two expanded rounds (numbers 1 and 2). The first is a Winchester Ranger 127 gr +P+ fired from a 4.5 barrel Glock 17. It expanded to a diameter of .59", penetrated to 14.6" and retained 114.9 grains of it's original weight! Not bad eh? This same round fired from a 4" barrel Glock 19 was even more impressive. It expanded to a whopping .65" while penetrating to a depth of 14.9" and retaining 114.5 grains in weight! That is just incredible for a 9mm. Farther down the page is the Ranger 147 gr. standard velocity JHP's. These too performed well and seemed to favor the longer barrels while not expanding as well in the shorter barrels.
So if I were asked to pick the best self defense ammo available for the 9mm, I would have to go with the 127 gr +P+ Ranger in 4" barrel pistols, either 127 or 147 gr loads with a 4.5" barel and though data wasn't shown for the 5" barrel, the 147 gr may actually perform best from it. Either round is a good one.
The listed velocity from the +P+ ammo fired from the Glock 17 was 1180 fps, so it doesn't seem that this round would be overly brutal to the shooter or the weapon. Most NATO spec 9mm 124 gr FMJ has a velocity of 1150 fps or greater. While I wouldn't want to use this ammo very often, I imagine most pistols should be capable of absorbing a standard 3 mag load of these in an emergency at least, plus the occassional round in training.
There were other rounds that actually expanded a little better than the Ranger, but none managed anywhere near the penetration. I saw one that expanded to approximately .70" in diameter, but it only penetrated to about 8". That said, I would take the Ranger's .65" expansion over the other one considering the Ranger is a much deeper penetrator, while not being really bad as far as overpenetration.
Now I just have to figure out where and if I can get this load. I know it is marketed by Winchester as a LEO only load, but it is my understanding that it isn't illegal for civilians to have and use, if they can find it. I have heard of some gun shops that stock it, as well as gun shows and some auction sites. But most LEO suppliers probably stock this, so if you are an LEO, this might be worth checking out. It looks as if this ammo is a top performer and could turn the 9mm (which is often regarded as a mouse)into a roaring lion! I have also heard that the Ranger has great loads for the .40 S&W and a very good 230 gr +P load for the .45 ACP.
Anyway I hope that some of this info was helpful to you folks. I had lots of fun looking at and comparing all the data. Ballistics data is really lots of fun but I am afraid my poor brain has absorbed more info than it is rated for! My head is hurting from reading so much. Oh, and thanks for the replies so far also.