Magpul PMAG 30 AR 300 B GEN M3 — 300 Blackout, Olive Drab Green

Magpul PMAG 30 AR 300 B GEN M3 — 300 BLK, OD Green

The Magpul PMAG 30 AR 300 B GEN M3 300 Blackout magazine solves a problem that 300 BLK shooters have quietly worked around for years — running a cartridge in a magazine designed for something else.

Magpul purpose-built this magazine specifically for 300 Blackout, using patented internal geometry that accommodates the wide variance in projectile weights and profiles found in the caliber. Because 300 BLK bullets range from lightweight supersonic loads to heavy subsonic rounds with dramatically different ogive profiles, a dedicated magazine matters more than most shooters expect. Additionally, the distinct rib design and uniquely smooth upper-half texture give this mag immediate visual and tactile differentiation from any 5.56 PMAG in your kit — because cross-loading a 300 BLK into a 5.56 chamber isn’t something you want to find out about downrange.

Built on the GEN M3 platform, the magazine uses Magpul’s current-generation impact- and crush-resistant polymer paired with a self-lubricating anti-tilt follower and a USGI-spec stainless steel spring. Furthermore, the paint pen dot matrix panel on the floorplate lets you mark and identify magazines quickly in the field. The OD Green finish adds immediate color-coded visual confirmation — particularly useful when running mixed calibers with mixed-color magazines.

Key Features — Magpul PMAG 30 AR 300 B GEN M3

• Purpose-designed internal geometry for 300 Blackout’s wide projectile weight and profile variance
• Distinct rib design and smooth upper texture for instant visual and tactile differentiation from 5.56 PMAGs
• GEN M3 impact- and crush-resistant polymer construction
• Anti-tilt, self-lubricating follower for consistent feeding
• USGI-spec stainless steel spring for corrosion resistance and long service life
• Paint pen dot matrix panel on floorplate for field identification marking
• Removable floorplate for maintenance and cleaning
• Made in the USA

Why This Product Stands Out

Most 300 BLK shooters have run standard 5.56 PMAGs without issue — and honestly, a lot of the time it works. However, “usually works” is the wrong standard for a magazine. The specific problem Magpul addresses here isn’t just reliability; it’s also safety. When you’re running 300 BLK and 5.56 rifles in the same setup, the visual and tactile differentiation built into this magazine provides a real physical layer of confirmation that you’re grabbing the right mag for the right gun. That’s not a marketing point — it’s a practical one.

Beyond safety differentiation, the internal geometry genuinely matters for 300 BLK. Because the cartridge spans everything from 78-grain supers to 220-grain subsonics, a magazine tuned specifically for that range of profiles feeds more consistently across the full spectrum than a 5.56 magazine asked to do double duty. Furthermore, the GEN M3 construction is the same platform trusted in duty and military use globally — which means the ODG variant carries identical structural specs, not a compromised colorway build.

The Olive Drab Green finish is notably useful for anyone running a color-coded magazine system. Similarly, the paint pen panels give you a secondary ID layer if you’re marking mags by load, stage, or owner. For competitive shooters, suppressors hosts, or anyone running a mixed-caliber AR setup, this magazine is the right tool for the specific job.

Ideal Use Cases

• 300 Blackout AR builds — supersonic and subsonic loads
• Mixed-caliber setups requiring visual/tactile magazine differentiation
• Suppressor hosts running 300 BLK subsonic
• Field use, duty use, or training where magazine identification matters
• Competitive shooting — 300 BLK USPSA, 3-gun, or tactical rifle

Technical Specifications

Compatibility Information

Platform Compatibility The PMAG 30 AR 300 B GEN M3 is compatible with AR-15 and M4-pattern rifles chambered in 300 Blackout. Because this magazine features modified internal geometry specifically for 300 BLK, it should not be used as a substitute in 5.56 NATO/223 Remington rifles. It is not designed for, nor compatible with, AK or other non-STANAG platforms.

Suppressor Hosts This magazine is particularly well-suited for 300 BLK suppressor builds where subsonic ammunition is used. Furthermore, the wide range of bullet profiles supported by the internal geometry makes it reliable across both subsonic and supersonic 300 BLK loads commonly run through suppressed hosts.

Manufacturer: Magpul Industries

Model: PMAG 30 AR 300 B GEN M3

Type: Rifle Magazine

Caliber: 300 Blackout

UPC: 840815150916

SKU: MAG800-ODG