Based on articles when the 357 SIG was new, it was intended to give .357 Magnum Revolver performance in a semi-auto pistol.
In a few states, DoT and Highway Patrol officers were issued the SIG because of superior car penetration vs. the .40 S&W. The trajectory advantage is questionable at pistol ranges.
Geoff
Who is primarily interested in point personal defense, not police work.