All right. Here I go with my personal opinion, which is free and worth every penny you pay for it.
After studying ANSI/SAAMI publication Z299, "
Voluntary Industry Performance Standards for Pressure and Velocity of Centerfire Pistol and Revolver Ammuinition for the Use of Commercial Manufacturers," I am assured that there is no, repeat NO, meaningful benefit from firing a +P (or, God forbid, a +P+) 9mm round from a pocket pistol with a barrel length of 3"+/-. All you would be doing is placing undue stress on all components of the pistol except the barrel itself.
With a 13-ounce pocket pistol chambered for the 9mm Parabellum round, such as the Rohrbaugh R9, what more effect does one expect of the piece in a close-quarters self-defense situation than what would be delivered by a quality standard-pressure, expanding hollow point such as the Gold Dot, Silver Tip, or Golden Saber? If you want a higher pressure round in 9mm, get a larger and heavier handgun. (Just know that it won't weigh in at 13 ounces and will probably not fit in your pocket.)
I seem to recall that one senior and esteemed member of this Forum has reported on a 9mm Hi-Power that "blew out" a grip panel with a high pressure round -- fortunately with no harm to the shooter.
Here is again some free opinion from a born "risk taker" who, in spite of the odds, has been lucky enough to have outlived most of his enemies and survived into his vigorous seventies --
1. Don't push the pressure limits of your guns.
2. Don't redline your sports cars.
3. Don't test the limits of the Navy SCUBA Dive Tables.
4. And never,
never, trust someone else's piton on a rock face.
