I can't be the only person on the planet that has trouble lining up the holes in a ball board with the muzzle of your rifle. So I added pegs to mine as shown in the picture.
To use it, simply place the pegs against the flats of the barrel and the ball will be lined up with the bore of the rifle.
The pegs and holes must be carefully laid out and of, course, will be specific to a barrel size and caliber. The ball board can also be used with round barreled guns just as well.
If anyone is interested, I can walk you through how to lay out the pegs and holes. It is easier than you might think.
Dale H