In 6mm Lee Navy caliber, the M1895 saw service with the United States Marines during the Spanish–American War, including the 1898 invasion of Guantanamo Bay, where a Marine battalion deployed four Colt guns (two of them borrowed from the USS Texas's armory).
The M1895 in 6mm Lee was also utilized by American Naval and Marine forces during the Philippine–American War, and the Boxer Rebellion, where it proved to be accurate and reliable. Around 1904 the Mexican government purchased 150 of these guns in 7mm Mauser caliber, and these guns were employed throughout the protracted Mexican Revolution. Use of the 7mm M1895 in the Mexican Revolution has been photographically documented, including the use of the gun by what appears to be a Villista.
Further south, the M1895 was also used by the Uruguayan Army against rebels during a late flare-up of the Uruguayan Civil War in 1904.
Canadian mounted troops successfully used .303 M1895 guns in the Second Boer War (1899–1902). In one spectacular rear guard action a Colt gun mounted on a light carriage was able to stop a pursuing Boer Cavalry unit. Winston Churchill, then a young Lieutenant in the South African Light Horse and a war correspondent, was impressed by the effect of the fire of a whole battery of these guns.
World War I:
The M1895/14 Colt–Browning saw use in France by some Canadian infantry formations. Deploying to France in 1915, the 21st Canadian Light Infantry Battalion used .303-caliber M1895/14 machine guns in combat. These guns saw significant combat but were soon replaced by Vickers machine guns. They were not taken out of combat however, but were instead given to equip formations of the Belgian Exile Army. The French also tested the Colt and some were used in early aircraft for testing. Additional Colt guns were sent to the Russians, who used them extensively.
After World War I, some Colt–Browning guns (possibly including the M1917/18 Marlin variants) saw use in the Russian Civil war. Its most spectacular use came during the Czech Legion's exodus from Russia, where the guns (either Colt–Browning M1914 or Marlin M1917 models) were photographed in sandbagged stations on the top of trains being used to transport the Legion as it withdrew from Soviet Russia. Many of these guns were also used in the Polish–Soviet War of 1920. At the outset of World War II, M1917 and M1918 Marlins were also sent to Britain for use by the Home Guard, but were never used in combat.
The last documented use of the type was by the US National Guard against striking miners in the Battle of Blair Mountain, West Virginia, U.S., in 1921.