This year marks the 150th anniversary of the Colt Model 1873, also known as "The Peacemaker" and the Single Action Army (SAA). Samuel Colt was a prolific designer of firearms, and this is one of his most well known.
I watched the engraver working on this barrel for a Peacemaker. It is marvelous to me how artistically talented some people are. He knows the pattern he wants to put on the barrel, and gently, with his hammer and chisel, cuts away at it leaving the pattern forever in the steel.