Most revolvers use #10 caps. I don't have a LeMat so I can't say what they take. Most people use Remington #10 caps. They fit well but I use CCI #10 which require a little more pressure to seat. Percussion caps vary in dimensions between manufacturers. You will want to use .454 balls with around 30 grains of black powder or a substitute such as Pyrodex. Pytodex is a straight across substitute measured by volume not by weight. Triple 7 is a little hotter so if you want the bp equivalent you can go 10% less by volume. BP needs a vegetable based lube to keep fouling soft. You can use a lubed wad under the ball or you can put straight lube over the balls. if you use something like Crisco over the balls it will melt and get blown all over the gun. If you use a petroleum based lube it makes bp fouling hard and difficult to clean. Modern gun cleaners do not work on bp fouling. The best thing to clean it with is hot soapy water. Balls must be made from pure lead. I don't know what the manual says to use for a powder charge but most manuals are lawyered up and the charges are wimpy. I use 30-35 grains of either 2F or 3F in my .44's. everybody says to use 3F but you can't tell any difference between them.