Tradition's Buckhunter is one option for a hunting black powder pistol. There are custom ones made out there from other inline parts. I do not have one, but accuracy would depend a lot on the load you work up and you. Some of them will take a 70 grain powder charge. If they shoot conicals or sabots you might have a good close range deer pistol there..

The trouble with the other black powder revolvers are they lack the knock down power to hunt anything too large. I have a .44 caliber New Army 1858 Black Powder Revolver. It shoots 25 grains of Goex FFFg and a .451 roundball with excellent accuracy. This is a lot of fun for rabbit and squirrel but I would not take it deer hunting. If I had to shoot a deer with it, I would make sure the animal was broadside, and within 25 yards of me....