You should get a short starter that has both a long and short stem for starting bullets or round balls - you probably have one already.
You should also get some special patches for shooting balls, they are made of a ticking and are different than cleaning patches. Can be bought pre-lubed.
0.490 is the correct size of ball.
Make sure your rifle is unprimed.
Let's also start with a clean barrel - no residue in it.
Dump your powder charge.
Center the lubed ball patch on the muzzle.
Center the ball in the patch, push down with your thumb so it stays in place.
Use the short little stem on the ball starter, center it on top of the round ball and give the top of the ball starter a good slam with the palm of your right hand.
The ball will go down into the bore to just below flush with the muzzle.
Switch to the longer stem on the ball starter, center it down the bore onto the round ball and whack the sucker with the palm of your right hand, and continue pushing downward till the ball starter hits the muzzle.
Switch to your ramrod (or better yet, buy a range-rod - much stronger) and push the ball to the charge.
When you encounter the charge give the ramrod two or three smart raps to ensure that it is firmly on the charge. Very important to do this every time.
Remove ramrod (they fly a hell of a long ways...)
Prime the nipple.
Let fly.
That is how we do it and our rifles are reliable and quite accurate. Flinters are another story. They are creations from hell and must be pampered or they will let you down.
Good luck, I buy the appropriate pre-cut, pre-lubed ball patches from T/C and use Hornady round balls. Also check into the relatively new saboted round balls from Hornady, makes shooting sidehammers much easier. Shoot very well in my rifles.
Always swab your bore after each shot to minimize buildup of powder residue, makes loading much easier.
