My oldest is a 1895 Colt Navy Model revolver in .38 Long Colt. I bought it for $75 plus tax back in 2002. It has a lot of wear and a truly awful DA trigger pull. I shoot a few rounds thru it every year.
The next oldest overall, and the oldest rifle, is a 1896 vintage RIC Lee Metford carbine. Paid $400 for that one.
1893 Turk Mauser made in 1894, GEW 98 Mauser 8mm from 1917, S&W Regulation Police .32 revolver from 1924, S&W .32 Hand Ejector from 1928, S&W 32-20 Hand Ejector from 1922.
All are fully functional and fun to shoot!
I’ve been trying to date this Brown Bess variant with little luck. It was hanging over the mantle in the 1770s Maine farmhouse my grandparents bought in the 1930s. It’s shorter than the standard issue musket, like an East India pattern (War of 1812-ish). Has Tower of London roll mark and British proof marks. The lock still works fine. However, there are details of the lock work that don’t match right and look earlier. Plus how did it end up in rural Maine?
Next oldest is a Springfield Model of 1870 Navy rifle in .50-70:
The oldest one I can actually date is an 1873 Trapdoor rifle made in 1884. I have an older caplock muzzleloader that arrived in Laramie, WY with the Union Pacific Railroad in 1868 so I know it’s at least that old. My best guess is it was made sometime in the 1850’s.