Beretta Model M9A1 Caliber: 9mm Luger The 92FS is such a popular gun in modern day media and it is also used by the U.S. military, like the U.S. Army, as their standard issue sidearm. Law Enforcement agencies use this weapon as their standard choice of 9mm like the LAPD. The model M9A1 is Beretta's updated version of the popular 92FS, designated M9 for military service, has picatinny rail built into the frame. It also has a new grip that uses horizontal lines instead of vertical. Looks more comfortable to me!