My 10mm, 40, and 357sig all use flat point bullets, it's called a meplat, as I understand, it allows for greater tissue disruption vs. a round bullet like you commonly see on 9mm, 380, 45acp. The square blunt end more or less tears through tissue than pushes tissue aside like the rounded or pointed bullet does.
Kind of a crude comparison..... what does more damage, being stabbed with a sharp pointy stick or a cut off square blunt stick of the same diameter.... Which heals faster???
Also commonly seen on large caliber solid hunting rounds, like 45-70, 454 Casull, 458win, and on up into big game like nitro rounds.. With big game, you want to cause as much damage to keep from being killed, and solids, while they penetrate good, don't expand, so the flat blunt point bullet helps with deep tissue disruption.