The current issue of BPCN has an article By Harvey Pennington on hunting with the 44-40. With BP of course ....
But - he used old UMC "balloon head" cases, a risky venture in my opinion. I've been present when a Dominion BP loaded "balloon head" case came apart in a rifle chamber, giving the shooter a face full of gas.
He loaded 36 grs FFg under Lyman 42798 bullets and chronoed them at 1219 FPS.