Ruger's New Model Blackhawk is a very stout handgun, and is pretty much ideal for the handgun hunter. In 45 Colt it will take very heavy loads, but if you're hunting deer, a 250-grain cast SWC around 1,000 fps is plenty. I've had good luck with Unique and HS-6 for moderate loads, and H110 or WW-296 for the real barn burners. Try handloads.com for a good rundown of what's possible with the 45 Colt.
Okie John