The Primary Weapons Systems MK116 Mod 1-M Compound in .223 Wylde (brand part no. MK1-CPP-223-16) is a semi-automatic AR-platform rifle built around PWS’s long-stroke piston operating system, combining a Mod 1 upper with a Mk1 Mod 2 lower. Primary Weapons Systems designed the long-stroke piston system to keep the AR-15’s core layout while cutting the maintenance burden of high-volume fire and adverse conditions, feeding from an included 30-round magazine through a 16.1-inch barrel. Among AR-platform rifles in the AR rifles category, the Compound favors shooters who want piston reliability without departing from the AR-15 form factor.

Key Specifications

• Chambered in .223 Wylde, compatible with .223 Remington and 5.56 NATO.
• Operates as a semi-automatic rifle using PWS’s long-stroke piston system.
• Combines a Mod 1 upper with a Mk1 Mod 2 lower.
• Features a 16.1-inch barrel.
• Ships with an included 30-round magazine.
• Part of the MK116 Mod 1-M model line.
• Gas system uses a 3-setting adjustable gas regulator.
• Fitted with a PWS FSC 556 muzzle device.
• Barrel is rifled at a 1-in-8 twist rate.

Frequently Asked Questions

What operating system does this rifle use? PWS’s long-stroke piston system, built to reduce maintenance in high-volume fire.

Does this rifle include a magazine? Yes, a 30-round magazine ships with the rifle.

Buy the PWS MK116 Compound .223 Wylde

Piston reliability without leaving the AR-15 form factor is exactly what the MK116 Compound delivers. Order it from our Lubbock, Texas gun shop for fast, insured shipping to your FFL.