M17 / M18 Modular Handgun
OEM: SIG Sauer
First Produced: 2017
Status: Active
Role: 9mm service sidearm
Primary Operator: U.S. Army / U.S. Marine Corps / U.S. Navy / U.S. Air Force
OEM Website: sigsauer.com
The M17 and M18 are the military variants of SIG Sauer's striker-fired P320, selected in 2017 under the Modular Handgun System program to replace the Beretta M9 as the standard service sidearm. The full-size M17 carries a 17-round magazine, while the compact M18 is issued primarily to Marine Corps, Air Force, and Navy personnel who need a shorter grip and slide.
The modular chassis design lets armorers change grip modules and slide assemblies without a serialized frame swap, and both pistols accept the Romeo1 Pro miniature red-dot sight out of the box, a first for U.S. general-issue handguns. More than 500,000 M17s and M18s have been delivered across the services since fielding began in 2018.
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