I too had little success with Lee conicals and found round balls to be both more accurate and much easier to load.
Accuracy improved if the powder was compressed slightly so I used 30 grains BP (by volume), 1/4" felt wad, .457" ball and Emmert's Lube over the ball.
Recently I started experimenting with 30 grain BP combustible paper cartridges (made out of cigarette paper) which did away with the need for wads but tended to leave unburnt residues in the chambers.
My final and most successful development was a 30 grain BP tinfoil cartridge made from kitchen aluminium foil. (Colt patented waterproof, machine-made tinfoil loads with picket bullets in the 1840s I think). Ignition was excellent provided I remembered to prick the base of each before loading and the chambers were clear after shooting.
Sadly, I'm a lousy pistol shot so I sold the Old Army a couple of weeks ago to raise money for a flintlock rifle. BP pistols are such fun though that I could well be tempted back by a Uberti Colt 1860.
Brian (founder member BCLBD) - British Campaign for Larger Barn Doors :haha: