These were all bottleneck cartridges with a large charge of powder, making the .45 version the most powerful handgun in the world for a time.

It used a unique long recoil rotating bolt action which ejected spent cartridges straight to the rear, and the feed mechanism is unusual in that it pulls cartridges backwards out of the magazine and then lifts them up into the breech face.

The Mars Automatic Pistol was rejected by the British War Office as a possible replacement for the Webley & Scott revolvers, then in service with the British Army, because of the unacceptably powerful recoil, considerable muzzle flash, and mechanical complexity.

The captain in charge of tests of the Mars at the Naval Gunnery School in 1902 observed, "No one who fired once with the pistol wished to shoot it again".

The Mars Automatic Pistol can also be used by the Scout class in the 2016 video game, Battlefield 1.