Thank you loadedround for your info, however I do go to hodgdon's site for other loads I've developed and they are a valuable resource but they don't list HS-6 powder for a MID range load higher than the cowboy saami pressures of 14000 CUP. They go straight to a hot rod powder like H-110 for the ruger listings. I've also followed John linebaugh suggestions for MID range data of 13gr HS-6 for 300gr cast bullets. I guess my main question would be, has anyone tried HS-6 for a 300gr jacketed bullet in 45 colt? I'll be launching them out of my Henry big boy lever and s&w 460v revolver so high end pressures are not a concern if I stay in a MID range listing.