I'm glad that we've established that Shiloh '63s DO NOT utilize a sleeve. Either that, or I own and/or have owned the only Shiloh '63s that do not.
No, you don't have brass cases to clean (although Pedersoli sells them for their rifles), but you do have a breech block to disassemble and clean thoroughly after EVERY use or you wind up with a frozen block. The flash hole clean out screw is frequently over looked and it seizes in place. Likewise the gas plate.
Instead you have the joy of preparing paper cases, a task that makes loading and cleaning brass cases seem simpler by comparison. Lots of different approaches to this, the easiest being Hahn tubes IF your rifle is a .54. Hahn doesn't make them for a .50. Check you tube for videos on preparing paper cases.
The Conant system used by Shiloh is less than perfect in that the gas seal isn't all that great. The gas plate doesn't really slide forward as intended and you will eventually suffer cavitation of the gas plate. This is accentuated by using loose powder, according to Shiloh. These are replaceable but require careful fitting and they are hard as hell. Ask me how I know ...... I haven't tried the rubber 'O' ring trick, but I will.
The '63s are a lot of gun and shoot well within their limitations. You will not be winning any BPCR matches with them. If you don't like the idea of shooting and cleaning cap & ball revolvers, the percussion '63s are NOT the rifle for you!
In the era, the percussion Sharps rifles were head and shoulders above the rifled muskets of the day insofar as rapidity of fire. As a skirmish rifle in the hands of Berdan's Sharpshooters, it was unbeatable.
It also has the distinction of being the ONLY non-British carbine design ever considered for adoption by the British, five cavalry regiments being armed with them. These were the earlier '59 slant breech models with a poor gas seal but they gave good service in India. It was also the only carbine they ever tested with a two piece stock.
The first thing the Brits did was remove the pellet primer and tape priming mechanisms, replacing them with standard musket nipples. They also had the calibre increased to .577 in order to use P53 Enfield bullets.
The major complaint was burned cuffs on expensive uniforms due to the flash around the breech block.
By the time the improved 'New Model '63' (vertical breech) came along, the Brits had adopted British pattern carbines, cancelling contracts with Robbins & Lawrence (marketers for Sharps), nearly forcing them into bankruptcy. The onset of the American Civil War saved them.