I've loaded powder less with my .32, .36, .40, .45 and .69 multiple times. For me, the easiest, unless there is someone along to hold the rifle, is to dribble 4F or 3F powder through the vent
or down the nipple seat, then replace the nipple or prime the pan and fire it out. Fooooooot onto the target or ground.
Most ball screws if home made from normal wood screws have a large diameter 'shank' which expands the ball quite a bit. The ball screws Track sells have a smaller shank but wider/deeper
'blades'. Screw it in a bit and pull and it usually pulls out. Clean the lead off the 'threads' and repeat. Screw it in a 1/2 turn or full, then pull. Do this until the ball comes out. It usually comes out the 3rd time. Screwing it all the way into the ball before pulling, usually expands the ball HARD into the bore,making pulling it very hard indeed. If you aren't using a clean shooting load (tight), any fouling buildup will make pulling the ball much harder. Likely easier out shoot it out. With flinter of caplock, I pour prime(3 or 4F) into the pan or nipple seat, then tilt the gun slightly and tap the top flat or breech with the knob on the end of my starter. The powder will trickle into the area behind the ball. Do this 3 times, then replace the nipple and cap it, or prime the pan and fire the ball out. If you don't see or hear the ball come out along with smoke, use your rod to make sure the bore is empty.