This seems like a good idea, reverse the hollow base and get a BIG hollow point. Attracted me once, too. The idea has been around for decades, and actual performance is sadly disappointing: the lead walls of the reversed base tend to readily fragment and along with the remaining lead in the base fail to penetrate. This questionable, highly variable performance will be further compromised by heavy clothing. The wound may be ugly, but superficial unlikely to incapacitate an assailant. It would be better to load bevel-base wadcutters within normal pressures but with enhanced velocity. Still better choice would be to scrounge-up some non + p nyclads.
Personally, after carrying at various times as an LEO, private investigator, or civilian and ccw instructor for many years, and after long discussions with professional ballisticians, I am hesitant to employ or recommend any ammunition except that which is loaded by one off the big companies (I would trust my own handloads for my own use, just as I do for hunting). The big guys have the best testing and quality control - by far!
