I've been told that Buffalo Bore loads the hottest loads commercially and actually uses actual weapons and not vented test barrels. I decided to look at their fastest loads in .357 and .40 S&W. I looked at the 158 JHC .357 VS 155 Grain in .40 S&W. Buffalo Bore warns against using their .40 in any fully unsupported barrel (Glocks). A snub in my opinion is anything under the historic service length barrel 4" to 5". Buffalo Bore's .40 S&W's test weapon is a Sig 229 3.75" barrel clocking 1040 FPS and a 3" J Frame S&W clocking 1398 FPS. The energy for the .40 is 372ft.lbs and for the .357 is 686 ft.lbs. I wouldn't want to shoot that from a J frame but from a K frame 2.5" or SP101 2.25"'/3" or better yet GP100 3" give me the .357.