CMMG MK4 T .300 AAC Blackout 16″ Rifle

Description

You’re looking at a solid, no-frills AR-platform rifle chambered in the versatile .300 AAC Blackout. The CMMG MK4 T .300 AAC Blackout 16″ Barrel RKM11 KeyMod Hand Guard Mil-Spec M4 Butt Stock Black 30rd Mag is a complete, ready-to-shoot carbine built on proven mil-spec patterns. It offers a practical entry point into the .300 BLK world without the premium price tag of boutique brands. For just $863.47, you get a functional tool that ships to Missouri and compliant US states, requiring only a standard FFL transfer for firearm purchases.

Here’s the thing—when you’re budget-conscious but want a rifle that works, you often have to choose between building it yourself or settling for a bare-bones factory option. The CMMG MK4 T splits the difference. It gives you a complete, reliable rifle from a reputable manufacturer, saving you the time and potential headaches of a first-time build. You’re paying for function over flash, and that’s a smart trade-off. The 16-inch barrel length is a practical choice, balancing the .300 BLK cartridge’s potential with a familiar, maneuverable carbine profile.

Key Features & Practical Value

The heart of this package is the .300 AAC Blackout chambering. This cartridge is the real value driver. It lets you run heavy, subsonic rounds suppressed for quiet shooting, or standard supersonic loads for effective reach, all from a standard AR-15 lower receiver with no modification. That’s versatility you don’t get with 5.56mm. The rifle comes with one 30-round magazine, getting you to the range immediately. The RKM11 KeyMod handguard provides ample real estate for lights or grips, though the KeyMod system itself is a budget-friendly choice—it works, but the accessory ecosystem has largely shifted to M-LOK.

Everything else is mil-spec. The M4 buttstock, trigger group, and controls are the same proven components used across the industry. This is a major benefit for the practical shooter. It means upgrades and replacements are cheap and everywhere. Want a different stock or pistol grip? Dozens of brands make compatible parts. The rifle weighs in at approximately 6.5 lbs unloaded, a standard weight for a 16-inch AR. This commonality keeps costs down and reliability up. CMMG isn’t reinventing the wheel; they’re assembling a dependable one at a good price.

Product Specifications

Specification	Detail
Caliber	.300 AAC Blackout
Barrel Length	16 Inches
Handguard	RKM11 KeyMod
Stock	Mil-Spec M4 Butt Stock
Magazine	1 x 30-Round
Operating System	Direct Impingement

Pros, Cons, and Who It’s For

Pros: The biggest advantage is the out-the-door price for a complete, name-brand .300 BLK rifle. The use of mil-spec parts guarantees wide compatibility and easy servicing. The 16-inch barrel makes it a straightforward rifle for hunters or recreational shooters who don’t want to deal with NFA paperwork for a short-barreled rifle (SBR). It’s truly drop-in ready.

Cons: The KeyMod handguard is a dated attachment system. While functional, the best and newest accessories often favor M-LOK. The trigger is a basic mil-spec unit—serviceable but not a precision instrument. This is a tool-grade rifle, so don’t expect fancy finishes or ambidextrous controls. You’re getting core functionality.

So who is this for? It’s perfect for the Missouri hunter wanting a compact, effective woods cartridge for medium game. It’s for the shooter who wants to experiment with .300 Blackout’s suppressed capabilities without a four-figure investment in the host rifle. It’s also a sensible choice for a home-defense role where over-penetration with 5.56mm is a concern. If your priority is a working rifle that doesn’t break the bank, this CMMG model hits the mark.

Frequently Asked Questions

Q: Will this rifle work with my existing AR-15 magazines and parts?

A: It uses standard .300 AAC Blackout magazines (included), which are typically the same as .223/5.56 mags but are marked differently to avoid confusion. Most lower parts, like triggers and grips, are mil-spec and fully compatible. The upper receiver is built for the .300 BLK cartridge, so you cannot safely swap a 5.56 upper onto a .300 BLK lower without verifying compatibility.

Q: Is the 16-inch barrel the best choice for .300 Blackout?

A: It’s the most flexible choice for a non-NFA firearm. A 16-inch barrel allows the cartridge to reach its full velocity potential with supersonic loads, making it effective out to 300+ yards. While .300 BLK is famous for short barrels, the 16-inch version loses little efficiency and keeps you compliant without tax stamps.

Q: Can I mount a suppressor on this rifle?

A: Yes, provided the barrel has the appropriate threading (typically 5/8×24 for .30 cal). You would need to verify the specific thread pattern of this CMMG barrel. Assuming it’s threaded, you can attach a .30 caliber suppressor after completing the required ATF Form 4 and paying the associated tax.

Ready to add this versatile, value-packed rifle to your collection? It’s available at firearms-missouri.com for Missouri residents and nationwide.