CMMG MAG MK9/AR15 4.6x30mm 40rd Magazine

The CMMG MAG MK9 is a 40-round polymer magazine chambered for 4.6x30mm. It is designed for use with AR-15 lower receivers and to feed the 4.6x30mm cartridge when paired with a CMMG FourSix upper. The magazine uses black polymer construction and presents exterior dimensions similar to many 30rd 5.56mm AR magazines for familiar handling.

Key Specifications

• The magazine holds 40 rounds.
• Chambered for the 4.6x30mm cartridge.
• Constructed from polymer for a lightweight profile.
• Finished in black.
• Intended application: centerfire pistol use as specified by the manufacturer.
• Compatible with AR-15 lower receivers when paired with an appropriate 4.6x30mm upper.
• Overall dimensions are listed as 1.25 x 3.90 x 9.45 (manufacturer listing).
• Height is listed as 1.2500 (manufacturer listing).
• Width is listed as 3.9000 (manufacturer listing).
• Length is listed as 9.4500 (manufacturer listing).

This magazine provides a high-capacity, polymer construction option for shooters using the 4.6x30mm cartridge in AR-style platforms. Its dimensions mirror familiar AR magazine geometry to simplify handling and fitment when assembling a compatible lower and FourSix upper, making it a practical choice for range and training use where 4.6x30mm capability is required.