When looking at load data for the 38spl round it would seem that the WB 150 PF is easily achieved. I tested my Cowboy knock down loads with 158grn bullets.
With an average of 969fps they gave a PF of 153. Well within the SASS max of 1400fps. As this was with low humidity and at 6,000ft I may have to up the charge a little to be comfortable wherever I travel.
All rounds tested were started with a clock held one step directly behind and at waist height both under cover and in the open. All rounds were recorded.
