Primary Weapon Systems Releases Sub-6-Pound .300 Blackout Rifle
Primary Weapon Systems dropped the MK107 MOD 2-M, a short-barreled rifle chambered in .300 Blackout that tips the scale at just 5.2 pounds complete. The gun ships with a 7.75-inch 416 stainless steel barrel cut at 1:5 twist, optimized for heavy-grain ammunition commonly used in suppressed fire. This weight and configuration make it a serious option for operators running cans and subsonic rounds downrange.
The barrel receives aggressive fluting to shed ounces without sacrificing rigidity. PWS machined the tube from 416 stainless, a material choice that resists corrosion during high-round-count suppressors work. The 1:5 twist stabilizes 220-grain and heavier .300 Blackout loads reliably. Accuracy expectations sit high—PWS claims sub-MOA groups with match ammunition when secured in a precision vice.
The rifle accepts standard AR pattern controls and magazines. Picatinny rails run on top and sides for optics and accessories. Gas operation uses PWS's piston system, proven in their other short-barrel builds. Charging handle sits ambidextrous. Bolt carrier group features chrome lined internals rated for 10,000+ rounds before inspection.
Why It Matters for Gun Owners
Carrier weight matters in real-world shooting. Five pounds loaded with a magnifier and mounted light still feels nimble in tight spaces. Police tactical units and private security teams demand this efficiency. Home defenders appreciate .300 Blackout's terminal performance indoors without over-penetration concerns that plague 5.56. Subsonic loads cut noise to hearing-safe levels when paired with a quality suppressor.
The MK107 MOD 2-M addresses a specific need: short, light, accurate. No guessing whether this gun delivers. PWS built reputation on piston-driven reliability and attention to detail. Their barrels hold tight tolerances. This SBR doesn't compromise on function to hit a weight target.
For shooters running suppressed setups, .300 Blackout makes sense ballistically. Heavier bullets preserve velocity and energy better than lighter 5.56 rounds over shorter distances. Inside 200 yards, the cartridge performs. Many operators prefer .300 Blackout for close-quarters work specifically because of this performance envelope and noise reduction.
Background
PWS has manufactured precision rifle components and complete rifles since 2010. Their founder spent time in military small arms development. That background shaped the company's engineering philosophy: measure twice, cut once. Every design detail serves a purpose. No unnecessary features. No weight waste.
The original MK107 earned respect in tactical circles. The MOD 2-M iteration refines the design further. Customers reported success with the previous version; this update addresses feedback from those field reports. The .300 Blackout platform itself has matured significantly since its 2011 introduction by Advanced Armament Corporation. Ammunition availability improved. Suppressors designed specifically for subsonic loads now dominate the market. Barrel manufacturers understand the cartridge's requirements better.
Short-barreled rifles chambered in .300 Blackout occupy a niche, but that niche pulls serious buyers. Dedicated hunters use them. Tactical professionals rely on them. Serious gun owners recognize their purpose and performance.
DownRange Bottom Line
The MK107 MOD 2-M represents PWS executing their design philosophy: deliver a purpose-built tool without compromise. Five pounds, accurate, piston-driven, .300 Blackout. That's the complete package. Pricing sits in the $2,200-$2,600 range depending on exact configuration and dealer. For serious shooters running suppressed systems, this rifle deserves consideration. PWS doesn't make disposable firearms. This one will shoot for decades with proper maintenance.
