$24.80
Availability: In Stock
Current Stock: Out of stock
The CMMG FourSix Magazine Mk4 is a purpose-built 4.6x30mm magazine designed for AR-15 shooters who want serious capacity without sacrificing ergonomics. Built from durable polymer, this magazine holds 40 rounds of 4.6x30mm ammunition while maintaining the exterior profile of a standard 30-round 5.56mm AR magazine—so it feeds reliably in any AR-15 lower receiver without looking out of place in your platform. If you're running a CMMG 4.6x30mm upper and want to maximize trigger time between reloads, this is the magazine built to keep you in the fight.
The FourSix Mk4 is engineered exclusively for the 4.6x30mm cartridge, so compatibility is straightforward: pair it with any AR-15 lower receiver and a CMMG 4.6x30mm upper, and you're ready for the range. The polymer construction keeps weight down while the 40-round capacity gives you a serious advantage in volume of fire—perfect for shooters who want to push their accuracy and speed without constant mag swaps.
Whether you're building a short-range tactical rifle, a home-defense AR, or an SBR that needs to punch above its weight class, the FourSix magazine gives you the firepower to back up your platform. The familiar form factor means it fits standard mag pouches and carriers, making it a no-fuss upgrade to your setup.
| Brand | CMMG |
| Product | FourSix Magazine Mk4 |
| Caliber | 4.6x30mm |
| Capacity | 40 rounds |
| Material | Polymer |
| Color | Black |
| Compatibility | AR-15 lower receivers |
Yes. The FourSix Mk4 is designed to fit any AR-15 lower receiver. However, it is engineered exclusively to feed 4.6x30mm ammunition, so you'll need a CMMG 4.6x30mm upper receiver to actually shoot the rounds it holds.
The FourSix Mk4 holds 40 rounds of 4.6x30mm while keeping the exterior dimensions similar to a standard 30-round 5.56mm magazine. This gives you extra capacity without a dramatically larger footprint that would affect ergonomics or fit in standard mag pouches.
You'll need an AR-15 lower receiver and a CMMG 4.6x30mm upper receiver to complete a functional rifle. The magazine pairs with both of those components to fire 4.6x30mm ammunition.
SKU: 115649528 • Weight: 1oz
Availability: In Stock
Current Stock: Out of stock
The CMMG FourSix Magazine Mk4 is a purpose-built 4.6x30mm magazine designed for AR-15 shooters who want serious capacity without sacrificing ergonomics. Built from durable polymer, this magazine holds 40 rounds of 4.6x30mm ammunition while maintaining the exterior profile of a standard 30-round 5.56mm AR magazine—so it feeds reliably in any AR-15 lower receiver without looking out of place in your platform. If you're running a CMMG 4.6x30mm upper and want to maximize trigger time between reloads, this is the magazine built to keep you in the fight.
The FourSix Mk4 is engineered exclusively for the 4.6x30mm cartridge, so compatibility is straightforward: pair it with any AR-15 lower receiver and a CMMG 4.6x30mm upper, and you're ready for the range. The polymer construction keeps weight down while the 40-round capacity gives you a serious advantage in volume of fire—perfect for shooters who want to push their accuracy and speed without constant mag swaps.
Whether you're building a short-range tactical rifle, a home-defense AR, or an SBR that needs to punch above its weight class, the FourSix magazine gives you the firepower to back up your platform. The familiar form factor means it fits standard mag pouches and carriers, making it a no-fuss upgrade to your setup.
| Brand | CMMG |
| Product | FourSix Magazine Mk4 |
| Caliber | 4.6x30mm |
| Capacity | 40 rounds |
| Material | Polymer |
| Color | Black |
| Compatibility | AR-15 lower receivers |
Yes. The FourSix Mk4 is designed to fit any AR-15 lower receiver. However, it is engineered exclusively to feed 4.6x30mm ammunition, so you'll need a CMMG 4.6x30mm upper receiver to actually shoot the rounds it holds.
The FourSix Mk4 holds 40 rounds of 4.6x30mm while keeping the exterior dimensions similar to a standard 30-round 5.56mm magazine. This gives you extra capacity without a dramatically larger footprint that would affect ergonomics or fit in standard mag pouches.
You'll need an AR-15 lower receiver and a CMMG 4.6x30mm upper receiver to complete a functional rifle. The magazine pairs with both of those components to fire 4.6x30mm ammunition.
SKU: 115649528 • Weight: 1oz