PWS MK1-M2R-6ARC-14PW MK114 MOD2 6ARC 14.5″

The PWS MK1-M2R-6ARC-14PW MK114 MOD2 in 6ARC with a 14.5-inch barrel is a long-stroke gas piston rifle that redefines reliability for the dedicated shooter. Built by Primary Weapons Systems—a company with over two decades of refining piston-driven AR platforms—this model delivers consistent performance in adverse conditions while maintaining the accuracy the 6mm ARC cartridge is known for. The PWS MK1-M2R-6ARC-14PW MK114 MOD2 6ARC 14.5-inch combines a hammer-forged barrel with a full-length top rail, offering a robust foundation for optics and accessories.

Manufacturer	Primary Weapons Systems (PWS)
Model	MK114 MOD2
Material	7075-T6 aluminum upper and lower receiver; 4140 chrome-moly steel barrel (per manufacturer specs)
Compatibility	6mm ARC ammunition; accepts standard AR-15 lower parts and magazines
Finish	Hard-coat anodized receiver; QPQ corrosion-resistant barrel finish
Weight	7.2 pounds (unloaded, per manufacturer specs)
Condition	New

Key Features

• Long-Stroke Gas Piston System — Why it matters: Reduces carbon fouling in the receiver and bolt carrier group, keeping the rifle running clean even after hundreds of rounds without lubrication, a proven advantage in sandy or wet environments.
• 14.5-Inch Hammer-Forged Barrel — Why it matters: The 1:7.5 twist rate stabilizes 95-108 grain 6mm ARC bullets for sub-MOA accuracy, while the chrome-moly steel construction extends barrel life beyond 10,000 rounds (per PWS field data).
• Full-Length M-LOK Handguard — Why it matters: Provides a continuous 12 o’clock Picatinny rail for mounting optics and a lightweight M-LOK interface at 3, 6, and 9 o’clock for accessories, keeping the rifle balanced at 7.2 pounds.
• Adjustable Gas Regulator — Why it matters: Allows the shooter to tune the gas system for suppressed or unsuppressed fire, reducing recoil impulse and ensuring reliable cycling with various ammunition loads.
• Ambidextrous Safety and Bolt Release — Why it matters: Enables quick manipulation from either shoulder, a practical feature for tactical shooters and left-handed users who need consistent operation under stress.

Who It’s For

This rifle is built for the discerning collector who values mechanical refinement and historical lineage. It suits the long-range enthusiast who wants a compact platform for hunting varmints or steel targets out to 800 yards, and the tactical shooter who demands a piston gun that runs dry and dirty without failure. If you appreciate the evolution of the AR platform from direct impingement to piston operation, the MK114 MOD2 is a piece of that history.

Pros & Cons

• Pros: Reliable piston action reduces cleaning frequency; accurate 6mm ARC barrel for long-range work; adjustable gas system for suppressor use; ambidextrous controls for left-handed shooters; full-length rail for mounting versatility.
• Cons: The 14.5-inch barrel requires a pinned and welded muzzle device to meet 16-inch overall length for NFA compliance, limiting muzzle device swaps without a gunsmith.

Comparison: PWS MK114 MOD2 vs. Geissele Super Duty vs. Zev Technologies AR-15

Feature	PWS MK114 MOD2	Geissele Super Duty	Zev Technologies AR-15
Operating System	Long-stroke gas piston	Direct impingement	Direct impingement
Caliber	6mm ARC	5.56 NATO	5.56 NATO
Barrel Length	14.5 inches	14.5 inches	16 inches
Weight	7.2 lbs	6.9 lbs	6.5 lbs
Gas Adjustment	Yes, adjustable regulator	No, fixed	No, fixed
MSRP	$2,309.95	$1,899.00	$2,199.00

FAQ

What is the barrel twist rate on the PWS MK114 MOD2 6ARC?

The barrel features a 1:7.5 twist rate, optimized for 6mm ARC bullets from 95 to 108 grains, delivering sub-MOA accuracy with match-grade ammunition.

Does the 14.5-inch barrel come with a pinned muzzle device?

Yes, the PWS MK114 MOD2 includes a pinned and welded flash hider to achieve the legal 16-inch overall length, making it NFA-compliant without a tax stamp.

Can I use standard AR-15 magazines with this rifle?

Yes, 6mm ARC uses standard AR-15 lower receivers and magazines. PWS recommends using dedicated 6mm ARC magazines for best reliability, but standard 5.56 magazines will function with reduced capacity.

How does the piston system affect accuracy compared to direct impingement?

The long-stroke piston system shifts the rifle’s balance slightly forward and adds reciprocating mass, but PWS has engineered the MK114 MOD2 to maintain sub-MOA accuracy. The trade-off is reduced felt recoil and cleaner operation, which many shooters prefer for rapid follow-up shots.

What is the warranty on this rifle?

PWS backs the MK114 MOD2 with a lifetime warranty against manufacturing defects. Transferable to original owner.

Trust & Delivery

• ✓ Nationwide delivery to all 50 states
• ✓ Ships within 1-2 business days
• ✓ 30-day return policy
• ✓ Secure checkout with encryption

Browse more from our Semi Auto Rifles collection, or explore AR-15 Uppers and 6mm ARC Ammunition.

Last updated: April 2026