I choose mine based on its reliability in the specific firearm it is going in. Not the brand/model of the firearm, the actual firearm itself. Only after shooting lots and determining which ammos are 100% reliable (that takes 100's of rounds of each, not just a few) do I start looking at other factors. I could not care less about the newest magic police bullet if it's not 100% reliable in the firearm it will be used in. Some of these supposed magic bullets cost $1.50 per shot. While I can afford that for carry, I cannot ("choose not" actually) to afford to buy 300 of them for initial reliability testing. I will first try last years magic bullet at half the price as my starting point. Revolvers are much simpler, significantly less testing is required. If I were ever in a shoot out, I pray that my opponent concentrated on buying expensive flying ashtray magic bullets and then did not test them or practice with them. My bigger fear would be the trained marksman with plain old FMJ. I would actually fear that marksman with .22LR more than a gangbanger with any caliber or bullet design. I'll take a .500mag to the arm over a .22LR to the heart any day.