While my preference for a carry gun is at least .40 caliber, and I practice and must qualify annually, I believe more important than the caliber is how well you can shoot the gun and hit what and where you are aiming at. As Bill Hickock was known to say, " you cannot shoot fast enough to make up for poor marksmanship". I will add, a 50 caliber is no better than a .357. .38 or .45 or .40 caliber if you are incapable of hitting your target under stress.