CMMG MK4 T SBN .223/5.56 16″ Rifle

Description

Picture this: a threat emerges in the low light of your property’s perimeter. You need a tool that bridges the gap between a compact home defense firearm and a capable patrol rifle—something that moves with purpose, delivers decisive authority, and won’t let you down when every second counts. That’s where the purpose-built engineering of the CMMG MK4 T SBN comes into play.

The CMMG MK4 T SBN (Salt Bath Nitride) .223/5.56×45 16″ Medium Weight Taper Profile Threaded Barrel Black Furniture 30rd is a factory-built, mil-spec AR-15 rifle featuring a durable Salt Bath Nitride finished barrel and a balanced medium-weight taper profile for enhanced handling and longevity. It’s a ready-to-deploy platform priced at $814.50, ships to Missouri and compliant US states, and requires an FFL transfer for firearm purchases.

Let’s talk about where this rifle earns its keep. The heart of any reliable AR is its barrel, and CMMG’s choice of a 16-inch medium taper profile threaded in 1/2×28 is a smart one. The taper reduces unnecessary weight out front without sacrificing the rigidity needed for consistent accuracy, whether you’re working through a box of ammo on the range or conducting essential drills. That threaded muzzle is ready for a flash hider, compensator, or suppressor mount—no gunsmithing required. The Salt Bath Nitride (SBN) treatment isn’t just a finish; it’s a surface hardening process that significantly increases barrel life, improves corrosion resistance, and aids in cleaning. This is a barrel built for the long haul.

The platform’s reliability is rooted in its full mil-spec compatibility. This means every component, from the bolt carrier group to the fire control group, interfaces with the vast ecosystem of AR-15 parts and accessories. Need a different handguard? The standard barrel nut accepts most drop-in options. Prefer a specific trigger? Standard pins mean it’s a straightforward swap. The included black furniture provides a solid, no-fuss foundation. The rifle ships with a 30-round magazine, giving you a standard capacity that’s practical for both training and defensive readiness. With an overall length hovering around 34-35 inches with the stock extended, it remains maneuverable in tight spaces while providing a full 16-inch barrel’s ballistic efficiency.

Specifications

Caliber	.223 Remington / 5.56x45mm NATO
Barrel	16″, Medium Taper Profile, 1:7 Twist, Threaded 1/2″-28
Barrel Finish	Salt Bath Nitride (SBN)
Overall Length	~34.5″ – 35.5″ (Stock Dependent)
Magazine Capacity	30 Rounds (Included)
Receiver & Furniture	Forged Aluminum, Black Finish

Here’s the thing—no tool is perfect for every single job, but understanding the trade-offs is key. The MK4 T SBN’s strengths are clear: you get a robust, corrosion-resistant barrel from a respected manufacturer, full parts compatibility, and a ready-to-run rifle out of the box. The mil-spec foundation is a huge pro for those who value customization and proven reliability. On the other hand, the included basic furniture is functional but will likely be the first thing an enthusiast upgrades. The medium taper barrel strikes a great balance, but if your sole mission is the absolute lightest possible build, a pencil profile might be a consideration. For the vast majority of users, however, this configuration hits a very practical sweet spot.

So who is this rifle for? It’s for the Missouri landowner who needs a dependable tool for property patrols and varmint control. It’s for the home defender who understands the advantages of the 5.56 cartridge in a responsibly configured platform. It’s also an excellent first AR-15 or a solid base for a custom build, as its quality core components won’t hold you back. You’re getting a genuine CMMG barrel and a solid foundation, all for a price that makes sense.

Frequently Asked Questions

Q: Is this rifle ready to shoot right away?

A: Yes, it is a complete, factory-built firearm. It ships with one 30-round magazine. You will need to supply ammunition and, as with any firearm, perform a basic function check and familiarization. Remember, an FFL transfer is required for firearm purchases.

Q: What optics or accessories will fit this rifle?

A: The upper receiver has a standard Picatinny rail for mounting optics, and the handguard has slots for attaching lights, grips, or sling mounts. The rifle is compatible with a massive range of AR-15 accessories from brands like Magpul, BCM, and SureFire.

Q: Can I use both .223 Remington and 5.56mm ammunition?

A: Yes. The barrel is chambered in 5.56x45mm NATO, which is designed to safely fire both 5.56mm and .223 Remington rounds. Always consult your owner’s manual and practice standard safety protocols.

This CMMG MK4 T SBN represents a focused approach to the modern rifle—built with a critical eye on durability where it matters most. See the full details and availability at firearms-missouri.com for Missouri residents and nationwide.