CMMG MK4 RCE .300 AAC Blackout 16″ Rifle

Description

The CMMG MK4 RCE .300 AAC Blackout 16″ Barrel, SV Muzzle Brake, RKM14 KeyMod Hand Guard, CTR Stock 30rd Mag is a complete, ready-to-fire rifle chambered in the versatile .300 AAC Blackout cartridge. It’s a factory-built AR-platform rifle designed for reliable performance right out of the box, offering a practical balance of power and platform familiarity at a competitive price point of $1133.91.

Key Features

• Versatile .300 AAC Blackout Chambering: Effective with both supersonic and subsonic ammunition, making it suitable for hunting, home defense, and suppressed shooting.
• Complete Rifle Package: Comes with a 30-round magazine, CTR stock, and SV muzzle brake—no need for immediate upgrades to start shooting.
• 16-Inch Barrel Length: Provides a good velocity balance without entering NFA-regulated territory, keeping it simple for most owners.
• RKM14 KeyMod Handguard: Offers a lightweight platform for mounting lights, grips, and other accessories to customize the rifle to your needs.
• Mil-Spec Compatibility: Built on a standard AR-15 pattern, so many aftermarket parts and triggers from brands like Geissele or LaRue are drop-in ready for easy customization.

Specifications & Details

Caliber	.300 AAC Blackout
Barrel Length	16 inches
Handguard	RKM14 KeyMod, 14-inch length
Stock	Magpul CTR
Muzzle Device	SV Muzzle Brake
Magazine Capacity	30 Rounds (included)

Here’s the thing—this rifle weighs in around 7.5 pounds unloaded, which is fairly standard for an AR of this configuration. The 16-inch barrel is the sweet spot for .300 Blackout, maximizing the cartridge’s potential without the paperwork of an SBR. The included Magpul CTR stock is a proven design that locks up tight to reduce wobble, a nice touch you often pay extra for on other budget rifles. It ships to Missouri and compliant US states, ready for your FFL transfer required for firearm purchases. The total package price sits at $1133.91, which is a solid figure when you break down the components versus buying a bare-bones rifle and upgrading it yourself.

Who This Rifle Is For

This CMMG MK4 RCE is for the shooter who wants a capable .300 Blackout rifle without the hassle and potential cost of a custom build. It’s ideal for Missouri hunters pursuing medium game like whitetail deer where the .300 BLK excels at shorter ranges. It’s also a smart choice for a home defense firearm, especially if you plan to eventually add a suppressor. Budget-conscious buyers who appreciate the flexibility of the .300 AAC Blackout round but want the reliability of a factory-built firearm from a known manufacturer like CMMG will find real value here. You get a working system, not a project.

Pros & Cons

Pros: The main advantage is its turn-key readiness. It fits out of the box with a solid magazine and a reputable stock already installed. The .300 Blackout chambering is its biggest selling point, offering more punch than 5.56mm in a similar-sized package, especially with heavier bullets. The price is competitive for a complete rifle from a brand like CMMG, often coming in lower than building a comparable rifle with similar-quality parts piece by piece.

Cons: The KeyMod handguard system, while functional, has largely been superseded by M-LOK in the accessory market, which might limit your rail section and direct-mount options. Ammunition for .300 AAC Blackout is more expensive and less common than 5.56x45mm NATO, so practice costs are higher. It’s not the lightest rifle on the market, but that’s the tradeoff for a full 16-inch barrel and a durable construction.

Frequently Asked Questions

Q: Can I use standard 5.56/.223 magazines with this .300 Blackout rifle?

A: Yes, in most cases. The .300 AAC Blackout round is designed to function reliably in standard AR-15 magazines originally made for 5.56mm. The included 30-round magazine is a good start, and you can use many other PMAGs or USGI aluminum mags. Just be sure to mark them clearly to avoid dangerous ammunition mix-ups.

Q: Is the muzzle brake removable if I want to install a suppressor?

A: Absolutely. The SV Muzzle Brake is threaded onto the standard 5/8×24 threads of the 16-inch barrel. You can remove it (using proper tools and technique) to direct-thread a compatible suppressor or install a muzzle device like a flash hider or compensator that works with your preferred suppressor’s quick-attach system.

Q: How does this compare to a basic 5.56 AR at a similar price?

A: You’re paying a slight premium for the .300 Blackout chambering itself. A 5.56 rifle might get you more features or a fancier handguard at this price. The value here is in the cartridge’s specialized performance—better energy with subsonic/suppressed fire and superior terminal ballistics from short barrels. If you don’t need those traits, a 5.56 rifle may be more economical to feed. But if you want .300 BLK performance without a custom build, this CMMG package makes a lot of sense.

Ready to add this versatile .300 Blackout rifle to your collection? It’s available at firearms-missouri.com for Missouri residents and nationwide. Contact your local FFL to coordinate a transfer.