i carry a glock 31 in 357 sig loaded with 110 grain corbon power ball.
the reason why i carry the caliber and load that i do is because I have read that the 357 sig round has great stopping power. as for the corbon powerball ammo. I read that it is designed to defeat barriers such as heavy clothing while mushrooming.
another load i carry is 124 grain speer gold dots.. I have always been a fan of speer ammo.