First try the .490 balls.
Here's some more helpful items:
1. A short starter or ball starter to help start the patched ball at the muzzle. It's a seating tool that looks like a ball with a short rod and a ball seater attached.
One can be made from a piece of dowel and a block of wood, or simply press the ball in using a block of wood (drilling a hole helps to center it).
(A thick dowel also makes a sturdy range rod, just put a handle on it.)
2. Nipple pick - a thin piece of wire or a pin to clear obstructions out of the nipple hole and flash channel.
3. Nipple wrench - helps to remove the nipple without marring it.
4. A powder flask or plastic funnel top for the 777 container to pour the powder into the measure without spilling it. Pour the powder over an open box to catch and recover any spilled powder.
****Remember if you have a misfire or if you load a ball without loading any powder (that's called a dry ball), putting a few grains of powder under the nipple can help to ignite the main charge or to discharge the dry ball.****