M27 IAR
Heckler & Koch · Assault Rifle · In Production · 2010
Also known as: Infantry Automatic Rifle, HK M27, M38 SDMR
Overview
The M27 IAR is a select-fire assault rifle chambered in 5.56x45mm NATO, produced by Heckler & Koch since 2010.
Specifications
| Weight (empty) | 3600 g (127.0 oz) |
| Weight (loaded) | 4080 g (143.9 oz) |
| Overall Length | 940 mm (37.01") |
| Folded Length | 838 mm (32.99") |
| Barrel Length | 420 mm (16.54") |
| Action Type | Gas Operated Short Stroke |
| Firing Mechanism | Hammer Fired |
| Trigger Type | Single Stage |
| Magazine Capacity | 30 rounds |
| Magazine Type | Detachable Box |
| Muzzle Velocity | 823 m/s (2700 fps) |
| Muzzle Energy | 1355 J (999 ft·lbf) |
| Effective Range | 550 m (601 yd) |
| Maximum Range | 3600 m (3937 yd) |
| Rate of Fire | 800 rpm |
| Barrel Rifling | Right Hand |
| Rifling Twist | 178 mm (7.01") |
| Number of Grooves | 6 |
| Frame Material | Aluminum |
| Barrel Material | Steel |
| Stock Material | Polymer |
| Finish | Matte Black |
Calibers
- 5.56x45mm NATO · primary · 5.56x45mm NATO — also known as 5.56mm NATO, 5.56x45mm, .223 Remington
Features
- Firing modes: Semi Automatic, Full Automatic
- Feed systems: Detachable Box Magazine
- Safety mechanisms: Ambidextrous Safety Selector, Firing Pin Safety
- Features: Free Floating Barrel, Cold Hammer Forged Barrel, Chrome Lined Bore, Adjustable Stock, Picatinny Rail System, Quad Rail Handguard, Stanag Magazine Compatible, Short Stroke Gas Piston, Closed Bolt Firing
Variants
- HK416 D16.5RS — Base Platform
- M38 SDMR — Designated Marksman
- M27 IAR Block II — Updated Production
Service history
Operators
- United States Marine Corps · adopted 2011
- U.S. Marine Corps Forces Special Operations Command · adopted 2014
Conflicts
- War in Afghanistan (2001-2021)
- Operation Inherent Resolve (2014-present)
Production
Estimated total produced: 15,000 · Production years: 2010-present
Approximately 15,000 rifles ordered by USMC. The M27 is exclusively used by the United States Marine Corps; no known export customers.
Origin
Country of origin: Germany
Notes
The USMC's decision to adopt the M27 as a standard-issue rifle was controversial, as it replaced a belt-fed squad automatic weapon with a magazine-fed rifle. Proponents argued the M27's superior accuracy and reliability made individual Marines more lethal, while critics questioned the loss of sustained suppressive fire capability. The USMC ordered approximately 15,000 M27s to equip all infantry riflemen beginning in 2018. The rifle achieves 2 MOA accuracy with standard service ammunition and has a barrel life exceeding 15,000 rounds. The M38 SDMR variant was adopted in 2017 to give squad-level marksman capability.
Background
The M27 IAR transformed from a niche squad automatic weapon replacement into the standard-issue rifle of the entire USMC infantry, making the Marines the only branch of the U.S. military to adopt a piston-driven rifle as their primary infantry weapon. The decision was championed by General Robert Neller, then-Commandant of the Marine Corps, who argued that accuracy kills more effectively than volume of fire.