CM7S Mags – 300 BLK – 10rd

CM7S 300 Blackout Bolt Action Magazine – 10-Round AICS

This 300 Blackout bolt action magazine is the 10-round Magpul PMAG 10 5.56 AC that Chattahoochee Munitions has tested and vetted for use in CM7S firearms chambered in 300 BLK. Its AICS-pattern design works with the CM7 chassis and provides the cartridge presentation needed for the CM7S bolt face to engage and feed 300 Blackout ammunition.

Magazine selection is particularly important when using a .223-based cartridge in an AICS-pattern bolt-action platform. The PMAG’s offset feed-lip geometry and single-stack, constant-curve internal design help position cartridges for proper bolt engagement. CM recommends this magazine based on testing conducted in the CM7S rather than simply assuming that every .223-pattern AICS magazine will feed 300 BLK reliably.

Explore the complete family of CM7S 300 Blackout firearms and barreled actions, or visit Sector 300 to compare the complete CM 300 Blackout ecosystem.

CM-Vetted for the CM7S

Chattahoochee Munitions vets the magazines offered for our firearms and their stated caliber applications. This 300 Blackout bolt action magazine has been tested with the CM7S platform and is the magazine CM recommends for its 300 BLK bolt-action firearms.

The underlying PMAG 10 5.56 AC is manufactured by Magpul as a 5.56×45 NATO and .223 Remington magazine for short-action AICS-pattern bottom metal. Magpul does not provide a general recommendation for using this magazine with 300 AAC Blackout. CM’s recommendation is specific to our testing of the magazine with the CM7S 300 BLK system.

This product should not be interpreted as a universal magazine recommendation for every AICS-pattern 300 Blackout firearm. Differences in actions, bolt faces, bottom metal, magazine positioning and ammunition can affect feeding. CM’s validation applies to the stated CM7S application.

Offset Feed-Lip Geometry

The PMAG 10 5.56 AC incorporates offset feed-lip geometry designed to maximize bolt-face engagement with .223-based cartridges. This addresses a common challenge encountered when small-diameter cartridges are used in AICS-pattern systems originally associated with larger short-action cartridges.

Proper bolt engagement helps the bolt face capture the cartridge as it moves forward from the magazine. The single-stack, constant-curve internal geometry maintains controlled cartridge presentation throughout the magazine’s 10-round capacity.

These design characteristics are important to the performance of a 300 Blackout bolt action magazine. They help support consistent feeding while preserving the detachable AICS-pattern magazine architecture used by the CM7 chassis.

Magazine Features

• CM application: Tested and vetted for CM7S firearms chambered in 300 BLK
• Capacity: 10 rounds in the CM7S 300 Blackout application
• Magazine pattern: Short-action AICS
• Manufacturer: Magpul Industries
• Manufacturer model: PMAG 10 5.56 AC
• Manufacturer SKU: MAG1100
• Construction: Impact- and crush-resistant GEN M3 polymer
• Feed geometry: Offset feed lips designed to improve bolt-face engagement
• Internal geometry: Single-stack, constant-curve design
• Follower: Self-lubricating follower for smooth movement
• Spring: Long-life stainless-steel spring
• Handling: Low-profile ribs with aggressive front and rear texture
• Floorplate: Flared for positive handling and removal
• Identification: Paint-pen dot matrix for caliber or load marking
• Maintenance: Quickly disassembles for inspection and cleaning
• Country of manufacture: Made and engineered in the USA

Positive Handling and Identification

Low-profile ribs and aggressive front and rear texturing give the shooter positive control when inserting or removing the magazine. The flared floorplate provides an additional gripping surface, which can be useful when removing the magazine from a chassis or retrieving it from a pouch.

A paint-pen dot matrix on the base allows the magazine to be clearly marked for 300 BLK. Dedicated identification is strongly recommended when the shooter also owns firearms chambered in .223 Remington or 5.56 NATO.

Clear caliber markings reduce the possibility of ammunition or magazine confusion. Always confirm the firearm’s chambering and the ammunition headstamp before loading.

Supersonic and Subsonic Ammunition

300 Blackout ammunition is available with a wide range of projectile weights and profiles. Lightweight supersonic loads and heavy subsonic loads can present differently as they move from the magazine into the chamber.

Although this 300 Blackout bolt action magazine has been vetted by CM for the CM7S, customers should function-test the particular ammunition they intend to use. Confirm feeding from a full magazine, feeding of the final cartridge and normal extraction and ejection before relying on a load for hunting or another critical application.

Inspection and Maintenance

The removable floorplate permits quick disassembly for routine cleaning. Periodically inspect the feed lips, follower, spring and magazine body for contamination or damage. Keep the interior free of excessive oil, dirt and debris that could interfere with follower movement.

Do not alter the feed lips or internal geometry. If the magazine develops visible damage or repeatable feeding problems, remove it from service and contact Chattahoochee Munitions for assistance.

Complete the CM7S System

This 300 Blackout bolt action magazine supports the complete CM7S family, including compact chassis firearms and CM7S barreled actions installed in compatible AICS-pattern systems. It provides a tested magazine solution for customers purchasing a complete CM7S firearm or completing a rifle around a CM7S barreled action.

For the manufacturer’s original 5.56/.223 specifications, dimensions and product information, visit the Magpul PMAG 10 5.56 AC product page.