I shot and recorded these loads a while back, but lately have gotten a hankering to shoot more .357 and figured it wouldn't hurt to post these results. The 4" barrel - S&W 686 The 6" barrel - Ruger Security Six There is a dramatic difference in velocity with slower powders, and particularly when the charge weight is higher (and correspondingly bullet weight lighter). First load: Rem 158 grain JHP / 16.2 gr H110 / R-P case / CCI 550 primer 4" barrel average velocity - 1225 fps 6" barrel average velocity - 1360 fps Second load: RCBS 150 gr cast SWC GC (cast in linotype, average weight 145 grains) / 16.8 gr W296 / R-P case / didn't record primer but probably CCI 550 4" barrel average velocity - 1223 fps 6" barrel average velocity - 1455 fps Third load: Remington 125 grain JHP / 20.5 gr W296 / R-P case / CCI 550 primer 4" barrel average velocity - 1464 fps 6" barrel average velocity - 1658 fps On load three, the load is mildly compressed and there is moderate deformation of the soft lead nose during bullet seating. Any more powder than that (and there is more room according to Hodgdon) and the nose is severely deformed. The recoil of load 3 is significant for the middle weight .357 revolver and the 4" 686 definitely handled it better. It's almost nasty in the slimmer, less muzzle heavy Security Six. Below: a night shot with the 4" 686 using a 110 gr JHP over a hefty charge of W296.