The attached picture of a .450 Revolver cartridge (what else !) made by UMC has a card wad around the primer pocket - probably to take up space. (It was common for manufacturers to seat bullets directly onto the blackpowder charge. The wad would raise the level of the blackpowder to the correct point for bullet seating. On UMC .450 rounds using smokeless powder a case cannelure was added to hold the bullet prior to crimping.)
This round has a smooth case and unmarked copper primer.
According to the UMC production ledger, UMC loaded the 450 from 1889 but that had a folded head. The solid head (shown here) was introduced in this caliber in 1893.
(1). Has anyone any documentary evidence as to when this wad was introduced and discontinued?
(2). Has anyone seen this on other calibers from this era?