Just picked up 5 boxes of Independence .357Mag JSP ammo...i can't find any info (not even on the box) on what the MV of this stuff is. Anybody know?....Thanks for any info on this.

Independence from Federal .357 mag 158gr JSP is listed at 1,240 fps just like all the Big 3 load it. That's from a 4" vented test barrel to simulate a revolver. Add or subtract for longer or shorter barrels. Different pistols with the same barrel lengths, even if made by the same manufacturer, may easily have 100 fps difference between each other so don't expect it to be right on the button if you actually run it over a chronograph.