According to contemporary, perhaps sensationalized accounts, the Krag's complex design was outclassed[1] by the 7mm 1893 Spanish Mauser during the Spanish–American War, and proved ill-suited for use in tropical locales such as Cuba and the Philippines.

During the American assault on the strategic Cuban city of Santiago, a small force of 750 Spanish troops armed with Model 1893 Mauser rifles defended positions on San Juan and Kettle hills.

The attacking force consisted of approximately 6,600 American soldiers, most of them regulars, armed with the then-new smokeless-powder Krag–Jørgensen rifle and supported by artillery and Gatling gun fire.

With the Krag's replacement with the Mauser-derived M1903, the rifle is tied for the shortest service life of any standard-issue firearm in US military history (1892–1903).

Phased out Krag rifles and carbines were also used by law enforcement agencies such as the U.S Marshals, Texas Rangers Division, and even bounty hunters and local town sheriffs and deputies in the American frontier.

From 1894 to September 1899 a 220-grain jacketed bullet loading was issued using 40 grains of nitrocelluose powder, which developed some 40,000 psi and a muzzle velocity of 2,000 feet per second (610 m/s) in the Krag rifle and 1,960 ft/s (600 m/s) in the shorter carbine.

In March 1900 the remaining stocks of this ammunition, some 3.5 million rounds, was returned to the arsenals, broken down, and reloaded back to the original 2,000 ft/s (610 m/s) specification.