Magpul PMAG GEN M3 AR-15 .300 AAC Blackout 30-Round Magazine - $11.49 Built to hold (30) rounds of ammunition. Will only hold 300 AAC Blackout rounds. Constructed of next-generation impact and crush resistant polymer. This magazine also comes equipped with a hi-tensile compression steel spring to

Magpul PMAG 30 Gen M3 300 Blackout AR-15 Magazine - 30 Round - $10.99 The PMAG 30 AR 300 B GEN M3 is a dedicated magazine for rifles chambered in 300 Blackout. While standard AR-15 magazines may be used for this cartridge, the potential danger exists to chamber and fire a 300 Blackout round in a