I have taken a grand total of one whitetail with my 5.5" Blackhawk & 45 Colt cylinder.

I used the Hornady 250 gr. XTP, 26 grains of H110, Fed. 155 primer, Starline case. This load averages 1293 fps. at 15 ft.

25 yard broadside ribcage shot, buck stumbled about 15 yards and was done. Had a golf ball size exit wound through far side ribs.

Good luck with your purchase and hunt!

Think.
It's not illegal, yet.