On nearly a daily basis, I receive at least one or two emails requesting recommendations on the "best" standard pressure 9mm factory load(s) for defensive use against human predators.
The truth of the matter is that I do not "know" which standard pressure load is best. I am not sure that anyone truly can know...other than in very general terms.
I can relate what I've seen in my own informal "tests" as well as "anecdotal" reports I've received over the years from folks using various loads.
With respect to 115-gr. 9mm JHP's, Federal's "Classic" JHP garnered nice comments from two people contacting me in the two years or so. Both were using service type 9mm handguns and both were able to hit their opponents in the "upper chest" and the shots were unobstructed by arms or other intermediate targets. One required two shots; the other, one. I was not able to get more specific locations on the hits. None of the three shots exited on either adult male felon. If memory serves, this load usually penetrates 10 to 11" of 10% ballistic gelatin and despite its not penetrating the 12" FBI protocol depth in 10% ballistic gelatin, it continues to enjoy a positive reputation as a defense load.
A newer standard pressure load that I've gotten a couple of positive "user reports" on is Speer's 124-gr. Gold Dot Hollow Point. I believe that it is used by the NYC Transit Police while NYPD uses the +P version. In my own informal expansion/penetration testing using super-saturated newsprint soaked for 24 hours and then drained 30 minutes before shooting, expansion has been consistent with penetration that should translate to between 12 and 13 inches in gelatin.
How well these loads would perform in shorter barreled 9mm's, I cannot say for sure simply because I do not shoot really small 9mm's very much. I can say that the Federal 115-gr. JHP averages just over 1100 ft/sec from a Glock 26. The Speer 124-gr. GDHP averaged 1061 ft/sec from the same pistol. Both fed and functioned reliably with more than acceptable accuracy. I have received one report from a fellow using the 124-gr. standard pressure Gold Dot in his Kahr P9. He hit his opponent in the "stomach area" at which time the bad guy ceased approaching with a knife and surrendered and sat (not "fell") down. (I have no further information on this one.)
At this point, some will be considering 147-gr. loads and I think that newer designs such as Speer's Gold Dot, Remington's Golden Saber or Winchester's Ranger or premium defensive loads such as "Supreme Elite Bonded" would probably perform just fine, though I have not personally "tested" the latter one. Gold Dots and Golden Sabers have consistently been accurate and reliable expanders for me in not only 9x19mm, but .44 Special, .45 Colt and .45 ACP.
Were I considering any load, I would check the general consensus at various sites and perform my own "unscientific tests", but would place all considerations very secondary to reliability in my individual handgun(s). After that would come individual expansion/penetration performance followed by accuracy. If reliability, expansion/penetration and accuracy appeared equivalent in one or more loads, I would more than likely opt for the less costly, but if I was not "sure" or if I just had that "nagging feeling" that the most expensive truly was best, I'd buy it. There are enough unknowns and uncertainty in the fear-filled time in the "dark place" without worrying about the quality of one's chosen ammunition.
Though standard pressure 9mm loads are not my usual first-choices for defensive 9mm ammo, I do have quite a bit of the Federal 115-gr. JHP on hand as well as the other mentioned loads in 124 and 147-gr. weights. It really doesn't matter to me which wound up in my defensive 9mm pistol.
Our ability to place our shots well under pressure is at least as much of a deciding factor in a deadly force situation's outcome as our ammo choice and probably more.
Best to all and good shooting.