The Magpul PMAG AR 300 Gen M3 Magazine (MPN MAG800-BLK) holds 30 rounds of .300 AAC Blackout and is built for AR-15-platform rifles.

Key Specifications

• Holds 30 rounds of .300 AAC Blackout.
• Built for the AR-15/AR-platform.
• Finished in black.
• Uses Magpul’s Gen M3 anti-tilt follower and stainless steel spring.
• Molded from impact-resistant polymer.
• Classified by Magpul as a Magazine.
• Carries the PMAG model designation.
• Sold as a single 1-pack.
• Manufactured by Magpul Industries.
• A dedicated .300 Blackout body, not just a 5.56 magazine loaded with .300 BLK.

Frequently Asked Questions

Can I use a 5.56 PMAG for .300 Blackout instead? This listing is Magpul’s dedicated .300 AAC Blackout-marked PMAG AR 300, built and marked specifically for that cartridge.

What rifles does this fit? It’s built for AR-15/AR-platform rifles chambered in .300 AAC Blackout.

Buy the Magpul PMAG AR 300 Magazine

Shop it directly from Magpul Industries, or browse the full AR Magazines selection at Schaefer Defense.