When Colt cast about for a name for their latest big revolver and came up with “New Service,” it was just before the turn of the 19th Century.

The big brute that got the new moniker was a first in many ways. It was the first revolver to have a DA and SA trigger system and a swing out cylinder, which adapted to many large-caliber cartridges.

In that period, the big revolver cartridge was king and Colt wanted a gun that got it done. A large, strong and heavy six-shot revolver, the New Service was made in great quantity—more than 350,000 units—over a time span of approximately 44 years—1898 to 1942.

The New Service was the service pistol of such police agencies as the Canadian Mounties, U.S. Border Patrol and New York State Troopers. However, its greatest single buyer was the U.S. Army, which bought approximately 155,000 of them for use in World War I.

These 1917 revolvers were chambered in .45 ACP, and required full-moon clips to properly work.

A popular Colt for many years, the New Service had multiple variations including a target model with adjustable sights and even a fancy version called the Shooting Master. Eventually however, the popularity waned to the point that the guns were in the catalog, but relatively few were made.

The pictured sample is one of the last guns made in the late 1930s, a rare .357 Mag.