It's probably more efficient for your player to just trade in his lever-action Winchester for a
Colt 1855 Revolving Rifle or 1873 Revolver Carbine, the former converted from caplock to cartridge. (The latter appears to be a very rare and custom-order rifle.)
__________________
"Life ... is an Oreo cookie." - J'onn J'onzz, 1991
"But mom, I don't wanna go back in the dungeon!"
The GURPS Marvel Universe Reboot Project
A-G,
H-R, and
S-Z, and its
not-a-wiki-really web adaptation.
Ranoc, a Muskets-and-Magery Renaissance Fantasy Setting