Magpul PMAG 30 AR 300 B Gen M3 Rifle Magazine Black .300 Blackout 30/rd

The Magpul PMAG 30 AR 300 B Gen M3 Rifle Magazine is a purpose-built feeding solution engineered specifically for .300 Blackout rifles. Since .300 Blackout's introduction, shooters have been forced to rely on magazines designed for 5.56 NATO, compromising reliability, bolt velocity optimization, and mag-well fit. This 30-round capacity magazine eliminates those compatibility issues and delivers the performance that subsonic and supersonic .300 BLK shooters demand. Whether you're running a dedicated upper, SBR, or precision rifle platform, this magazine delivers consistent round-nose and hollow-point feeding across both velocity regimes.

Built to Magpul's Gen M3 specification, this magazine features aggressive feed lips optimized for .300 Blackout's larger diameter (.308-inch) compared to 5.56 rounds, ensuring zero double-feeds or nose-dives. The reinforced polymer construction withstands field abuse, temperature cycling, and repeated loading cycles without loss of spring tension—critical for suppressed fire where bolt velocity can vary dramatically. The witness holes allow rapid round-count verification, and the removable, self-lubricating follower reduces friction for smooth extraction under pressure. Its compact 3 x 1 x 7.5-inch profile fits standard AR lower magwells without modification while maintaining the full 30-round count.

Operators running .300 Blackout uppers—from law enforcement precision rifle teams to civilian shooters pursuing subsonic and supersonic accuracy—benefit immediately from purpose-designed magazine geometry that eliminates feeding failures and optimizes bolt carrier velocity consistency. This magazine is fully compatible with any modern AR-15 platform using .300 Blackout, including pinned-barrel configurations and short-barreled rifles. Stock multiple magazines for dedicated .300 BLK builds; the 0.81 lb weight per magazine is negligible compared to reliability gains. For shooters transitioning from borrowed 5.56 mags, this represents a significant real-world performance upgrade.