The rationale behind the 9mm Federal never made sense. Federal decided in the 1980’s that sport shooters needed a revolver cartridge that duplicated the ballistics of the standard 9mm Parabellum, much the same as the 45 Auto Rim was for the 45 ACP. After the new cartridge was launched, someone pointed out to them that the 9mm Federal was almost exactly the same dimensions as the 38 S&W, and with thousands of old, weak 38 S&W top-break revolvers floating around, this was a very expensive lawsuit just waiting to happen if someone fired these high-pressured rounds in old guns. It was quietly retired in the the early 90’s. (Erlmeier, Brandt Ref. 119A).