[Ian0351]

That my point in writing about the Miami shootout was to mention that it was because of this critical failure of ammunition that the FBI began looking for a better caliber for duty carry. Although several of the agents were carrying S&W .357 magnums, they were loaded with .38 special to reduce recoil and cost, as well as S&W Parrabellum 9mm autopistols. After several tests in the lab and at the range in which the 10mm auto was developed, they decided on the .40 caliber because it was easier for smaller men and women to acquire killing shots (the 10mm kicks like a .357) without sacrificing in expansion, penetration and kinetic energy at impact, also known as knockdown power.
Don't argue with me, argue with wikipedia:http://en.wikipedia.org/wiki/10mm_auto