After many years and many millions of dollars extorted from US Taxpayers expended, the FBI determined the best "man stopper" round of all was the 125 gr .357 Magnum hollow point.
They then bought the .40 Smith & Wesson, in Glock and SIG. SIG took the test results and necked a .40 S&W case down to .355 inches, loaded it with a 125gr HP bullet and called the result the SIG 357 (TM) Note: No decimal in the name, despite everyone who posts sticking the "." in every now and again.
Geoff
Who at least knows the money was not spent without some kind of result. Sigh.