I'm not sure about the specifics of the powder (I have sent off for some info on it) but IMR has a powder, Trail Boss,targeted at the cowboy actionblack powder revolver/cartridge rifle market. It is bulkier than standard smokeless powders to aid in not overcharging a case and may be closer to BP on a volumn basis (not sure but hope the info requested will show how close). One of the loads listed on their site is for 45-70 and a 405 bullet using 13gr by weight and developing around 25000 CUP, not that different from some loads used in many inlines. Since this is designed and marketed for use in some versions of black powder cartridge guns my question would be, would it be appropriate for other BP designed guns.

Just a thought, not wanting to start a big argument.