First of all, you only get so much power from a handgun. Period. Stopping threats comes from correct shot placement either to the CNS, (brain or upper spine) or the various blood rich organs as the heart, liver, or thoratic or femoral blood vessels. So the ultimate goal of handgun is really reliability. As close to 100% cycling reliability as possible. After that, bullet designs can be experimented with, to provide better performance, so long as reliability, as close to 100%, is not comprimised. One of my favorite is the Federa Premium Hydra-Shok, in 165 and 180 grain. The have great bullet shape for max reliability and functioning, and readily expand to act on attackers, and somewhat limit penetration on walls etc. Good shooting!