Primary Weapons Systems MK1 MOD 1-M BLEM Upper Receiver Assembly – 300 Blackout, 9.75″ Barrel

PWS MK1 MOD 1-M BLEM Upper Receiver Assembly – 300 Blackout, 9.75″ Barrel

Elevate your AR-15 build with the Primary Weapons Systems MK1 MOD 1-M BLEM upper receiver assembly, chambered in 300 Blackout with a 9.75″ barrel. This factory-blemished unit offers the same exceptional performance and durability as standard PWS uppers at a reduced price, making it an ideal choice for budget-conscious shooters seeking premium quality. Designed for suppressed applications and close-quarters use, this upper combines innovative engineering with rugged construction to deliver reliable operation in demanding conditions.

Enhanced Long-Stroke Piston System

The MK1 MOD 1-M features PWS’s proprietary long-stroke piston operating system, which significantly reduces fouling and heat transfer to the bolt carrier group compared to direct impingement systems. This results in cleaner internals, extended component life, and smoother cycling, especially when using suppressors. The system is optimized for 300 Blackout ammunition, ensuring consistent ejection and feeding with both supersonic and subsonic loads.

Optimized for 300 Blackout Performance

Chambered in 300 Blackout, this upper is perfect for hunters, home defenders, and tactical enthusiasts. The 9.75″ barrel length provides an optimal balance of velocity and maneuverability, making it suitable for short-barreled rifle (SBR) or pistol configurations. The 1:7 twist rate stabilizes a wide range of bullet weights, from lightweight 110-grain rounds to heavy 220-grain subsonics, ensuring accuracy and reliability across various applications.

BLEM Condition – Full Functionality at a Discount

This upper is sold as a BLEM (blemish), meaning it may have minor cosmetic imperfections such as scratches, discolorations, or machining marks that do not affect performance. All components are factory-tested and fully functional, backed by PWS’s reputation for quality. It’s an excellent opportunity to acquire a high-end upper at a more accessible price point.

Key Features and Benefits

• Long-Stroke Piston System: Reduces fouling, improves reliability with suppressors, and extends maintenance intervals.
• 300 Blackout Chambering: Versatile for hunting, defense, and suppressed shooting with optimal barrel length.
• BLEM Savings: Cosmetic flaws only, with full performance and warranty coverage from PWS.
• Durable Construction: Made from 7075-T6 aluminum with a hardcoat anodized finish for corrosion resistance.
• Enhanced Ergonomics: Includes an ambidextrous charging handle and M-LOK compatible handguard for accessory mounting.

Specifications Overview

This upper receiver assembly is ready to mount on any mil-spec AR-15 lower receiver, requiring no additional gunsmithing. It includes a complete bolt carrier group and charging handle, making it a drop-in solution for quick builds. The handguard features a full-length top rail for optics and backup sights, with M-LOK slots at the 3, 6, and 9 o’clock positions for lights, grips, and other accessories.

Why Buy from Texas Gun Store?

At Texas Gun Store, we combine expertise with a commitment to customer satisfaction. Our team includes experienced shooters and gunsmiths who test and vet products like the PWS MK1 MOD 1-M to ensure they meet high standards. We offer fast shipping, secure transactions, and dedicated support for all your firearm needs. Shop with confidence knowing you’re dealing with a trusted Texas Gun Store retailer focused on quality and service.

FAQ

• What does BLEM mean? BLEM indicates cosmetic imperfections that do not affect function; all parts are factory-tested.
• Is this upper compatible with my AR-15 lower? Yes, it fits standard mil-spec AR-15 lowers.
• Does it include a bolt carrier group and charging handle? Yes, it comes as a complete assembly.
• Is it suitable for suppressed use? Absolutely, the piston system excels with suppressors.
• What is the warranty? PWS provides a limited lifetime warranty on all components.