Magpul is now shipping the PMAG 30 AR 300 B Gen M3 for .300 Blackout. You may be wondering why such a magazine even needs to exist but Magpul already read your mind…
Why a Dedicated 300 BLK Mag?
While some .300 Blackout® ammo runs consistently in 5.56 magazines for some users, others have found it to be problematic. At the request of some demanding professional users, we have designed an ultra-reliable magazine dedicated to handling the challenges of various 300 BLK ammunition types.
Optimizes Round Stack
300 BLK rounds come in a variety of shapes and sizes, and some don’t interface correctly with the contact areas in a 5.56 mag. This can ultimately cause stoppages. By designing a PMAG specifically for .300 Blackout, we were able to optimize the round stack for the increasing variety of 300 BLK projectiles.
Minimizes Side Pressure and Friction
Dust or suppressor fouling magnify the problem—especially with certain subsonic rounds. This creates side pressure within the mag, adding friction and slowing the stack movement upwards. This is a geometry issue that our PMAG 30 AR 300 B is engineered to solve.
Avoids Caliber Misidentification
The dedicated PMAG for 300 BLK includes tactile and visual cues that differentiate it from 5.56 PMAGs for those who need to switch types of ammunition rapidly. This helps to avoid dangerous misidentifications and cross loading.
Maintains PMAG Reliability
Like all PMAGs, the PMAG 30 AR 300 B GEN M3 magazine features a long-life USGI-spec stainless steel spring, four-way anti-tilt follower and constant-curve internal geometry for reliable feeding.
See the PMAG 30 AR 300 B Gen M3 for .300 Blackout at Magpul.com
Wonder if this mag would work with 7.62×39.
I doubt it. The 7.62×39 has a significant taper to its case which is why 7.62×39 magazine tend to have a very curved shape.