Magpul PMAG 30 GEN M3 .300 BLK MCT - AR-15 Magazine

A magazine built specifically for the .300 Blackout — because a 5.56 magazine isn't. The Magpul PMAG 30 AR 300 B GEN M3 uses patented internal geometry modified specifically for the wide range of projectile weights and shapes found in .300 BLK, with distinct visual and tactile external differences that prevent dangerous cross-loading with 5.56 magazines in a multi-caliber environment.

The Magpul PMAG 30 GEN M3 .300 BLK is a 30-round polymer magazine designed specifically for AR-15-pattern rifles chambered in .300 Blackout, featuring modified internal geometry for consistent feeding across subsonic and supersonic loads and distinct visual and tactile differentiation from 5.56 NATO PMAGs.

Three features make this the mandatory magazine choice for dedicated .300 BLK builds. Patented modified internal geometry accommodates the large variance in projectile weights and shapes found in .300 BLK cartridges — from lightweight supersonic loads to heavy 200-plus-grain subsonic projectiles — delivering more consistent feeding across all load types than a standard 5.56 PMAG can provide. A distinct rib design and smooth upper-half texture provide both visual and tactile differentiation from 5.56 PMAGs, making it immediately identifiable by sight or feel in low light or high-stress conditions — a critical safety feature in a shooter's kit where both .300 BLK and 5.56 rifles are present. All GEN M3 standard features carry forward: impact- and crush-resistant polymer, easily removable floorplate, paint-pen dot matrix, and compatibility with all PMAG accessories and Tactile Lock Plates.

Compatible with AR-15-pattern lower receivers chambered in .300 Blackout only. Not for use with 5.56 NATO or .223 Rem upper assemblies. Medium Coyote Tan color.

Impact- and crush-resistant GEN M3 polymer. Removable floorplate. Paint-pen dot matrix. Made in the USA.

Purpose-built for dedicated .300 BLK AR-15 builds, suppressed subsonic configurations, and any multi-caliber environment where magazine cross-loading prevention is as important as feeding reliability.

By Magpul. Made in the USA. Standard Magpul warranty applies.