I'm convinced what sold the military on the 320 was the modular fire control assembly, which counts as the actual firearm, that allows all sorts of configurations to be built without having to go back to Congress to get money for a new pistol. Do the Parachute Ski Marines need some 14-shot, 357 SIGs with short barrels? Order a bunch of "repair" parts and put them together, and you don't have to deal with politicians demanding that a new pistol be built in their congressional district.