Blackhawk44 is right. Don't discount that round ball.
Millions of men have fallen to the "puny" .36 caliber round ball that weighs about 80 grains.
The late gun writer Elmer Keith said in his book, "Sixguns" that nothing is quite so deadly, size for size, as a pure lead ball driven with a hefty charge of black powder.
Keith also spoke of an old man he knew that hunted the last of the California grizzlies. He used a Colt Dragoon, sat up in a tree, had bait at the base of the tree, and shot the grizzly at the base of the skull with that old Dragoon. I don't know if that old man used balls or conicals but I would suspect he used a ball.
Though I've never taken a deer with a cap and ball sixguns, I've read of others that have. Some have used conicals, other used balls.
More important than the projectile is the marksmanship behind it. Your range should be limited to the distance at which you can place all 5 or 6 shots into a 6-inch paper plate, without fail.
And that's not from a benchrest, but from a standing position with two hands.
Frankly, I feel a .44-caliber ball --- when properly placed in the heart, neck or head --- would bring down a deer in short order.
The biggest problem is resisting the temptation to take shots beyond the ball's capability, such as when the deer is quartering away or two you. In these examples, the ball will likely stop before it reaches a vital area.
For hunting deer, you may wish to try Hodgdon Triple 7. Hodgdon's maximum load for the Ruger Old Army is 35 grains of Triple 7, giving a ball just under 1,000 fps.
If you use conicals, you have to sacrifice powder to accomodate the longer projectile in the chamber.
However, this sacrifice may be worth it, to get a heavier bullet. Others have reported success against deer with the conical, within reasonable ranges (25 yards or less).
The Lee conical bulllet is a good one. Lee also offers it in a hollowpoint version, but only for the Ruger Old Army. You may wish to try that version.
Casting hollowpoint bullets is slower and more aggravating. And I'm not sure that the hollowpoint will do any good. Most hollowpoints need a little over 1,000 feet per second to expand reliably.
I use the regular Lee conical in my Uberti-made copy of the Remington 1858 and my Pietta-made copy of the Colt 1860 Army.
To date, the Lee design is the most accurate conical I've found. But that's really not saying much.
Most conicals deliver 4 to 6-inch groups at 25 yards from a benchrest (six shots). A lead ball, properly loaded, will often cut that group size in half. I've occasionally had my Colt 2nd generation 1851 Navy put six balls into a 1" circle at 25 yards from a benchrest but it doesn't do this often. Perhaps it's just a fluke. However, it will typically deliver 2 or 3-inch groups at 25 yards from a benchrest, which makes it more accurate than many modern handguns out there.
In summation, I wouldn't totally write off the lead ball. Nor would I discount the slower-moving conical.
As I said before, I've never shot a deer with my cap and ball sixguns so I can't positively say what works. Others in here likely have harvested deer with a cap and ball and may help you.
Good luck!
