The Mosin Nagant is tied for the Mauser and the Lee Enfield as the military rifle that was used by the most countries in the most conflicts over the longest time. It had a front line service life of probably 70 + years-adopted by Imperial Russia in
1891, my Chinese Type 54 -Vietnam bringback- has a manufacturing date of 1960. There are plenty of variations-Tzarist ones graduated in arshins, Soviet ones grduated in meters, transitional ones, round receivers, hexagonal ones, Finnish ones, Finnish Army captures, Soviet ones without the "SA" cartouche showing Finnish capture, carbines, Dragoon rifles, etc.