SWORD International Mk 18 Mod 1 Mjolnir
SWORD International · Sniper Rifle · In Production · 2015
Also known as: Mjolnir, SWORD Mk-18, Mk 18 Mjolnir, SA-ASR
Overview
The SWORD International Mk 18 Mod 1 Mjolnir is a semi-automatic extreme-distance precision rifle chambered in .338 Lapua Magnum, designed to provide bolt-action-level accuracy in a rapid-fire platform. Named after Thor's hammer from Norse mythology, the Mjolnir uses SWORD's proprietary self-regulating short-stroke gas piston system that automatically balances gas pressure for optimal cycling without the over-gassing that plagues many semi-automatic magnum platforms. The AR-pattern ergonomics make the rifle immediately familiar to any operator trained on the M4/M16 family, while the .338 Lapua chambering extends effective engagement range well beyond a mile. At just 5.5 kg empty, the Mk 18 is remarkably lightweight for a semi-automatic .338 Lapua platform, making it practical for dismounted operations where a bolt-action rifle of equivalent capability would impose a significant weight penalty.
Specifications
| Weight (empty) | 5489 g (193.6 oz) |
| Weight (loaded) | 6000 g (211.6 oz) |
| Overall Length | 1143 mm (45.00") |
| Barrel Length | 610 mm (24.02") |
| Action Type | Gas Operated Short Stroke Piston |
| Firing Mechanism | Rotating Bolt |
| Trigger Type | Two Stage |
| Magazine Capacity | 10 rounds |
| Magazine Type | Detachable Box |
| Muzzle Velocity | 900 m/s (2953 fps) |
| Muzzle Energy | 6570 J (4846 ft·lbf) |
| Effective Range | 1600 m (1750 yd) |
| Maximum Range | 5000 m (5468 yd) |
| Barrel Rifling | Right Hand |
| Rifling Twist | 254 mm (10.00") |
| Number of Grooves | 6 |
| Frame Material | Aluminum Alloy |
| Barrel Material | Chrome Moly Vanadium Steel |
| Stock Material | Polymer |
| Finish | Cerakote |
Calibers
- .338 Lapua Magnum · primary — also known as 8.6x70mm, 8.58x70mm, .338 Lapua Mag
- .300 Norma Magnum — also known as .300 NM, 7.62x65mm
Features
- Firing modes: Semi Automatic
- Feed systems: Detachable Box Magazine
- Safety mechanisms: Ambidextrous Safety, Firing Pin Safety
- Features: Short Stroke Piston, Self Regulating Gas System, Free Floating Barrel, Picatinny Rail, Adjustable Stock, Suppressor Ready, Ambidextrous Controls, Ar Pattern Ergonomics
Variants
- SWORD Mk 18 Mod 0 — Original
- SWORD Mk 18 .300 Norma Magnum — Caliber Variant
- SWORD MK18 SA-ASR — Advanced Sniper
Service history
Operators
- United States Special Operations Command
Production
Production years: 2015-present
Limited production for military evaluation and civilian sales. SWORD International is a small specialty manufacturer.
Origin
Country of origin: United States
Notes
The Mk 18 designation is SWORD International's own nomenclature and should not be confused with the US Navy's Mk 18 CQBR (a 10.3-inch barreled M4 variant). The self-regulating gas system is a key differentiator: it adjusts automatically based on ammunition pressure, temperature, and suppressor use without requiring manual gas block adjustment. The Mod 0 variant featured a 22-inch barrel, while the Mod 1 extended to 24 inches for improved .338 Lapua ballistics. The SA-ASR (Semi-Automatic Advanced Sniper Rifle) variant adds .300 Norma Magnum and .338 Norma Magnum chamberings. SWORD has actively pursued US SOF contracts for the platform as a semi-auto alternative to bolt-action .338 systems.
Background
Named after the legendary hammer of the Norse god Thor, the Mjolnir was designed to deliver devastating power at extreme range with the speed of a semi-automatic action. SWORD International engineered the rifle specifically to give special operations snipers the ability to engage multiple targets beyond a mile without the slow cycling of a bolt action -- essentially bringing a .338 Lapua machine gun's firepower to a precision rifle package.