The Super Black Hawk has a much heavier frame and cylinder to accomodate the pressures of a .44 Mag. I don't even know if they make the Super in .45 Colt. Many loading manuals use a Black Hawk for testing the .45 LC and they keep the velocities and pressures way down. I know guys who have tried to approach .44 Mag ballistics with a .45 LC in Black Hawks and one guy [not too smart] blew one up. Nevertheless, a 250 grain bullet at 800 fps ought to be enough for whitetails. [It wouldn't be a legal hunting handgun for any big game here in Colorado because it lacks power. We have a minimum kinetic energy requirement of 550 ft./lbs at 50 yards and the .45 LC falls well short of that.]
Yikes, you've not been paying attention to the Handgunning world, as of late.
The .45 Colt cal. Ruger Blackhawk can safely shoot 335gr. hard cast lead bullets at 1,200 fps, give or take a few fps. Wyoming has similar "performance laws" and Buffalo Bore Ammunition, since it's a "Factory Load", makes the .45 Colt a legitimate Big Game cartridge.
Hodgdon's Data Manual #26 carries the "Ruger Only" loads and is most informative.
Approaching .44 mag. ballistics is easy with the .45 Colt, just not with lightweight bullets. It "shines on" with 300's, 325's and 335 grain bullets.
Perhaps a trip over to John Linebaugh's web site would offer you some eye opening data?
Link
HERE. Check out his 'Writings' section and look for "Dissolving the Myth....."
Happy Trails,
flatgate
PS This new fangled stainless thing, in .45 Colt cal., shoots the above loads very easily.