[How do you get a ball starter down the chamber?
Isn't the action in the way?/QUOTE]
Viewed from the rear, there's a "trough" cut in the top of the frame behind the breech block. When the action is open, you have straight line access into the chamber.
Some years back, I knew a Skirmisher who shot a Sharps in NSSA carbine matches. Here's how he achieved rapid, accurate fire:
He had a bunch of clear plastic tubes, 6 or 8 inches long and I guess half inch diameter. These served as his "cartridges" AND short starter combined.
He modified his Sharps bullet mould to produce a reduced diameter heel on his hard cast bullets (he always insisted on HARD lead) which just fit in the plastic tubes, so the bullets "corked" the tubes. (He had the other ends capped shut.) Of course the tubes held the powder charges.
On the line, he would hold the carbine at waist level, pointed downrange of course, action open. He'd grab a cartridge tube from his cartridge box and jam the bullet all the way into the chamber so it engaged the rifling, give the tube a little twist and shake to release the bullet and dump the (heavy!) powder charge, then toss the now empty tube on the ground. Cap her up and "...point her North. If twenty of 'em won't clear out all of Yankeedom, then I'm a liar, that's all."
As I recall, his Sharps struck me as a PITA, and few Skirmishers used them. He had to re-build the gas seal on the breech-block on a regular basis, as it would wear out. Of course, he shot A LOT. But I had always wanted a Sharps, until I met him.