Give me your cylinder throat diameter and I'll guarantee that the bullets will be large enough to size for a perfect fit. The WLN 325 gr is the meanest hardest hitting bullet in the world for the Blackhawk if you load it to full power. It will do 1500 fps quite easily, which is meaner than any North American animal needs, at either end of the gun. If you get a 280 or 300 gr WFN and load it to somewhere between 1200 and 1400 fps the critters will be ready for skinning just as quickly as with the big power, and you'll probably be able to shoot more accurately. Pain has a way of makeing shooters blink and flinch when putting pressure on the trigger, so I hear anyhow.
By the way. For those who crave max power, a 350 gr WLN is the meanest in the long cylinder guns, like Redhawks, Anaconda, etc., where a .5 nose length will chamber without extending past the cylinder mouths.