The SIG Sauer M17 and M18 are service pistols derived from the SIG Sauer P320 in use with the United States Armed Forces. The M17 is the full-sized model whereas the M18 is the shorter length carry model. Both models have been adopted by the Army, Navy, Marine Corps, Air Force, and Space Force. The pistol replaced the Beretta M9, as well as several other handguns across the services. The M17 has better accuracy and tighter dispersion than the Beretta M9.