SIG Sauer P320 M18
SIG Sauer, Inc. · Pistol · In Production · 2017
Also known as: M18, XM18, MHS Compact, P320-M18
Overview
The SIG Sauer P320 M18 is a semi-automatic pistol chambered in 9x19mm Parabellum, produced by SIG Sauer, Inc.
Specifications
| Weight (empty) | 797 g (28.1 oz) |
| Weight (loaded) | 1010 g (35.6 oz) |
| Overall Length | 183 mm (7.20") |
| Barrel Length | 99 mm (3.90") |
| Height | 140 mm (5.51") |
| Width | 41 mm (1.61") |
| Sight Radius | 147 mm (5.79") |
| Action Type | Short Recoil |
| Firing Mechanism | Striker Fired |
| Trigger Type | Single Action |
| Trigger Pull | 29 N (6.5 lbf) |
| Magazine Capacity | 17 rounds |
| Magazine Type | Detachable Box |
| Muzzle Velocity | 350 m/s (1148 fps) |
| Muzzle Energy | 493 J (364 ft·lbf) |
| Effective Range | 50 m (55 yd) |
| Maximum Range | 1800 m (1968 yd) |
| Barrel Rifling | Right Hand |
| Rifling Twist | 254 mm (10.00") |
| Number of Grooves | 6 |
| Frame Material | Polymer |
| Slide Material | Stainless Steel |
| Barrel Material | Carbon Steel |
| Finish | Coyote Pvd |
Calibers
- 9x19mm Parabellum · primary · 9mm NATO — also known as 9mm Luger, 9mm NATO, 9x19mm
Features
- Firing modes: Semi Automatic
- Feed systems: Detachable Box Magazine
- Safety mechanisms: Striker Safety, Disconnect Safety, Manual Thumb Safety
- Features: Modular Grip System, Optics Ready, Accessory Rail, Night Sights, Ambidextrous Safety, Reversible Mag Release, Coyote Tan Finish, Manual Safety
Variants
- SIG Sauer P320 M17 — Full Size
- SIG Sauer M18 Commemorative — Limited Edition
Base model
Service history
Operators
- United States Army · adopted 2017 · as M18
- United States Marine Corps · adopted 2019 · as M18
- United States Navy · adopted 2019 · as M18
- United States Air Force · adopted 2019 · as M18
- United States Space Force · adopted 2019 · as M18
Conflicts
- War in Afghanistan (2001-2021)
- Operation Inherent Resolve (2014-present)
Production
Estimated total produced: 226,000 · Production years: 2017-present
Approximately 226,000 M18 units planned across Navy (61,000), Marines (35,000), and Air Force (130,000 combined M17/M18); civilian P320-M18 production is additional
Origin
Country of origin: United States
Notes
The M18 differs from the M17 primarily in barrel length (3.9 inches vs. 4.7 inches) and slide length, while sharing the same carry-size grip module, fire control unit, and magazine compatibility. The U.S. Navy chose the M18 exclusively (61,000 units planned), while the Marine Corps ordered 35,000 units. The Air Force was the largest M18 customer with 130,000 units planned across both M17 and M18 configurations. The civilian P320-M18 commercial variant was introduced in 2020 and ships with one 17-round and two 21-round steel magazines. Unlike the military version, the civilian model lacks the anti-tampering mechanism but is otherwise dimensionally identical. The Coast Guard is notably the only U.S. military branch that did not adopt the M17/M18 system, instead selecting the Glock 19 Gen5 MOS.
Background
The M18 became the first pistol in U.S. military history to be simultaneously adopted across all five armed service branches that carry sidearms (Army, Navy, Marines, Air Force, and Space Force). The Marine Corps, which had traditionally been one of the last holdouts with the M9A1 and M45A1 (a modernized 1911), fully transitioned to the M18 as their standard-issue sidearm. The Navy's exclusive selection of the compact M18 over the full-size M17 reflected the service's preference for a more concealable sidearm suited to shipboard and special operations environments.