I have a Marlin 1894 Cowboy in 45 Colt, and a iron framed Uberti Henry in 44-40. Both are accurate and pleasant to shoot, the Henry will easily cut playing cards edgewise offhand at 25 yards. I have in fact killed two crows at 200 yards with the Henry.
On the other hand, if I were to hunt deer and had to choose between the two rifles, I would take the Marlin in 45 colt. Loaded with a 250 grain Keith style bullet and 8.5 grains of Unique, it is a really reliable killer, and will shoot through and through the shoulders of a deer at 100 yards. The other side of the coin is that I once shot a coyote on the shoulder with the 44-40 Henry, and it didn't go all the way through. I just think the 45 Colt is a much more effective cartridge.
An excellent report on field effectiveness here. This is why, after 40 years of shooting critters, the 45 Colt is the only revolver cartridge we keep on the place. From a sixgun or carbine, anything you'll need to do is easily accomplished with the 45's original ballistics. These days I use 8.5 grains of Universal and a Lee 452-255-RF.
