I’m not so sure. I’ve spoken with a fellow who cuts down these revolvers and he said that 35 grns is the max charge before powder is wasted from either 3 or 3.5” (I don’t recall which). But my thinking is when we see pics of the flash I have a hard time believing excess powder isn’t consumed in that fireball. But what I’ve also read from one who put out a white sheet is that what’s collected does not burn, that it’s the waste materials and not unburned powder.
35 grains is all that'll fit in a 60 Army or .44 Remington so that part's true. It might all be burned in an 8" barrel but I find it hard to believe it's all consumed in 3.5"s. That's more powder than I shoot in my Maynard carbine. More than is needed but if you like smoke & fire......