[BP Hunter]

i've noticed that there are alot of factory cowboy load ammunition. i am planning to use a conversion cylinder for my 1851 .36 cal . navy and my .44 cal. old army. is there a brand that i can trust?

[taralon]

I'd shoot the Black Hills ammo. I've shot some ultramax, but the powder was incredibly dirty, and was full of some sort of cornmeal looking filler. It actually took me longer to clean the gun after shooting that stuff than with black/substitutes.

[georgeduz]

you can use any lead low charge target load .you can by a use gun at the prices they charge for a con.kit,

[Howdy Doody]

Though I don't shoot 51's I have noticed most folks have their best luck with a hollow based 38 cal bullet when using their conversions. You would probably have to cast and reload for that.
Goex is loading some ammo called Black Dawg now. Good reports on that, but it may not be in big supply yet, since it is fairly new.