Magpul PMAG 20 AR 300 B GEN M3 – 20-Round .300 Blackout Magazine

The Magpul PMAG 20 AR 300 B GEN M3 is a dedicated 20-round magazine designed specifically for rifles chambered in .300 AAC Blackout (300 BLK). Unlike traditional magazines originally built for 5.56x45mm, this purpose-built PMAG enhances reliability, safety, and performance for 300 BLK shooters.

Optimized for .300 Blackout Performance

Using standard 5.56 magazines for .300 BLK can lead to feeding issues and potential catastrophic failures if rounds are mistakenly chambered in the wrong rifle. The PMAG 20 AR 300 B eliminates these risks with a design that fully supports the unique geometry of 300 BLK rounds, ensuring smooth and reliable cycling.

Compact & Maneuverable Design

The 20-round capacity offers a more compact and concealable profile compared to the larger PMAG 30 AR 300 B. This size is ideal for short-barreled rifles (SBRs), pistols, and tactical applications, where maneuverability is critical.

Enhanced Safety & Differentiation

To prevent cross-loading mistakes between 5.56 and 300 BLK, this magazine features a unique ribbed texture and distinct upper-half design. These visual and tactile differences allow shooters to quickly identify and separate their magazines, reducing the risk of chambering the wrong caliber.

GEN M3 Durability & Performance Features

The PMAG 20 AR 300 B incorporates all the advanced features of Magpul’s GEN M3 line, including:
✔ Impact & Crush-Resistant Polymer – Built to withstand harsh conditions.
✔ Aggressive Front & Rear Texture – Ensures a firm grip even in wet or muddy environments.
✔ Easily Removable Slim Floor Plate – Streamlined for easy maintenance.
✔ Paint Pen Dot Matrix – Allows quick magazine marking for easy identification.

Made in the USA – Trusted by Shooters Worldwide

Proudly made in the USA, the Magpul PMAG 20 AR 300 B GEN M3 is trusted by shooters, law enforcement, and military personnel for its superior performance, reliability, and safety.

Upgrade your .300 BLK rifle with a magazine designed for the job—choose the Magpul PMAG 20 AR 300 B GEN M3 for unmatched reliability and functionality.