Re: Colt 1851 Navy
Yep, keeps the wedge from coming all the way out, and losing it.
Remember, these revolvers were made for customers that were often hundreds of miles from the nearest supply or repair point. If a part broke or was lost, they had to repair it themselves or make a new part.
And if you lost the wedge on hostile ground, your life was in jeopardy.
I've read that cap and ball revolvers retained their popularity into the 1880s, especially in remote areas, because they didn't require a specialized cartridge like the newfangled guns. As long as you had caps, scrap lead, powder and a bullet mould, you could keep a cap and ball revolver going.
Reloading for cartridge guns apparently didn't become too common until the 1880s.
More than a few old Colt revolvers have surfaced with homemade repairs because of missing or broken parts. Unfortunately, these handmade parts are often replaced with factory parts and discarded.
Oh, the stories these old Colts with their handmade parts might tell, if they could speak!
"Therein do I see an ugly cat. Smoke. Fire. Brimstone. A vast desert. Holes in parchment. The ugly cat is much amused." --- The quantrains of Gatodamus (1503-1566)