Pistol Duelling was once an Olympic Sport
Duelling Pistol Shooting was an Olympic sport. in 1906 in Athens and in the 1912 Stockholm Games.
However instead of shooting at each other, they shot at frock coated mannequins with targets on their chests.
The gun caliber allowed was between 7.5 and 12mm, with a barrel maximum length of 30cm.
Greece, Sweden, France and Italy all medalled.
https://www.topendsports.com/events/discontinued/shooting-duelling-pistol.htm