The Beretta M9 is a 919mm Parabellum pistol adopted by the United States Armed Forces in 1985. The M9 won a competition in the 1980's to replace the M1911A1 as the primary sidearm of the U.S. military, beating many other contenders, and only narrowly defeating the P226 for cost reasons. It officially entered service in 1990 and remains the official standard issue sidearm of military branches including the Army.
Another popular choice with airsofters the M9 is offered in different variations including manually operated spring guns, powerful gas blow back guns, and even as electric airsoft guns. Though its gas blow-back version is the most popular choice for its unrivaled realism that often includes full metal builds, realistic take-down features, and a powerful 350+ FPS performance.