MAGPUL PMAG 20 AR 300 B GEN M3 BLK

Description

The PMAG 20 AR 300 B GEN M3 is built specifically for shooters running .300 Blackout in a compact or suppressed platform. Before dedicated 300 BLK magazines existed, shooters relied on standard 5.56x45mm magazines, which introduced real reliability compromises — the geometries of the two cartridges differ enough that feeding inconsistencies were a known problem, not just a theoretical one. Beyond reliability, there was a more serious concern: a 300 BLK round can chamber and fire in a 5.56-barreled rifle with catastrophic results. Using a visually and tactilely distinct magazine is a practical safeguard against that kind of mix-up at the range or in the field.

Magpul addresses both problems here. The ribbed body and smoother upper-half texture set this magazine apart from every other PMAG at a glance and by feel alone, so the difference is apparent even in low light or under stress. The 20-round body is shorter than the 30-round variant, which reduces the overall package when running a short-barreled upper or operating in tight spaces — a meaningful trade-off if maneuverability matters more to you than round count.

Construction follows the GEN M3 standard: the polymer is formulated for impact and crush resistance, the floor plate removes easily without tools, and a paint pen dot matrix is molded in for unit marking or personal identification. An integrated dust and impact cover protects the feed lips and follower when the magazine is not in use. Compatibility extends to Colt-spec AR15/M4 platforms, HK 416, MR556A1, M27 IAR, FN SCAR MK 16/16S, British SA-80, and similar pattern rifles. Made in the USA.