CHM,
Prairie Dawg has given you the best answer.
Noz get's confused when he uses .36 caliber because they roll out of his 1860s if he lowers his barrels.
But he is right about some posters giving you .44 data. This has become a problem since Pietta started making their "fictional" or whatever you want to call it .44 caliber 1851 revolvers. When you say 1851 to long time percussion revolver shooters we immediately assume .36 caliber.
I personally use 20 grains in a '51 or in a '61 because I also have a wad in there. I have used up to 22 grains for shooting at critters.
I, like Noz primarily shoot .44s and I shoot heavier loads than he does. Dawg is right about the 86 grain ball making a wimpy ding on steel targets. I would shoot my 1861s and my other Navy revolvers like 1851 and Leech and Rigdon Confederate Navy "copies" more if it weren't for that problem and the spotters missing the hit. I almost exclusively shoot 1860s in competition.
I was reading about your balls bouncing off, that doesn't surprise me with those lighter loads. With 12 grains you may not have been getting good compression on your powder. Your balls needs to be firmly seated against your powder to be safe and to work correctly. Air gaps between bullet and powder with BP is a no-no.
I have seen .36 cal. balls bounce off of a plywood backstop and after watching the young man shooting it I noticed he was barely seating the balls in the chamber and he was using a very short spout on a plastic powder measure. I talked to him a minute and after his next cylinder full I convinced him to let me load one round and shoot it with a fuller chamber. I don't know what the charge was but he was impressed because the gun boomed and it definitely made a hole in the backstop. It took two other shooters backing me up to convince him I wasn't telling him to load some "magnum" charge. I told him to go to a local gun store I knew and ask for a 20 grain spout from their black powder guy and to tell him I had sent him. I don't know if he ever went.
Navy models are fun to shoot and point very well for most people. A 20 grain load is what was recommended by Colt in one of their old publications. Of course those were meant for combat. You can shoot lower charges for target, but with .36 caliber 20 grains to 22 grains is still a very, very low pressure and pleasant to shoot load. 20 grains is actually equivalent to a wimpy standard velocity .380 ACP load but in a relatively heavy pistol. Very easy and pleasant to shoot.
The best to you...make sure you seat those balls firmly against the powder.
~Mako