Magpul’s New PMAG 30 AR 300 B Gen M3 Mags for 300BLK

Just in time for SHOT Show 2017 Magpul just announced another new product right after their debut of their new X-22 Backpacker Stock, this time they unveiled their new PMAG 30 AR 300 B Gen M3 Mags for the 300 BLK cartridge. Why would Magpul release a 300 BLK specific mag when you can use 5.56 mags with 300 BLK? While you can use 5.56 mags with 300 BLK ammo some mags have feeding issues when using some of the various 300 BLK bullet weights and profiles. These new PMAGS should help alleviate this.

Along with the same features as Magpul’s other Gen M3 mags the new PMAG AR 300 B Gen M3 mags have an “optimized internal geometry” that works with the various bullet profiles used with 300 BLK ammo. The new Magpul 300 BLK PMAGs also have a distinct rib design that gives shooters a “visual and tactile difference” from any other PMAG to help prevent accidentally shooting a 300 BLK round in a rifle chambered for 5.56, which I think is a pretty neat feature. Shooting a 300 BLK round in a 5.56 rifle has happened before, it’s more common than you think actually. The new PMAGs for 300 BLK will be available around Spring 2017 and should retail for $15.95. Check out for more info.



Ray I.

Long time gun enthusiast, archery noob, Mazda fan, Sci-Fi nerd, Whiskey drinker, online marketer and blogger. My daily firearms musings can be found over at my gun blog and Instagram.

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  • Do they work with 7.62×40 Wilson Tactical? That would be needlessly neat.

    Also, LOL, the industry is finally catching on to what they should have done in the first place.

    • JumpIf NotZero

      The three people at Wilson who own guns in that clambering sure would happy I guess.

    • Blake

      Seeing as how the rounds are almost identical I would be shocked if they didn’t.

  • RSG

    I’ve had trouble in the past and have had to download my mags with 220 grain subs to feed properly in pmags. I suspect stronger springs, too, considering the bullets are 4 times heavier than what they were designed for.

    • Don

      Lancer mags work perfect, I have never had a failure. And they don’t require any modifications. And they answer the second issue the new pmags addressed, they look different than the pmags so you never confuse the two.

  • Edeco

    o.O confusing title

  • Jerry

    We’re past the market tagline of “just change your barrel it’s easy” to “change your barrel, get an adjustable gas block, tune your buffer weight and gas setting, test various mags to find what ones work and with what ammo, and pay twice the price of 5.56 for a niche round”.

    But hey, at least you’ll be able to hunt with your AR in some states with caliber restrictions…

  • treefroggy

    Why not just effin’ mark the mags “300BLK” in bright red or orange letters ?