Knight's Armament Rifles, Uppers & Suppressors | Boss Firearms

Knight's Armament Rifles, Upper Receiver Kits & the M110 Suppressor-

C. Reed Knight Jr. founded Knight's Armament Company to build equipment for U.S. Special Operations Forces. Working with AR-15 inventor Eugene Stoner, KAC developed the SR-25, one of the most respected rifles of the modern era, along with advanced suppressors and the RAS rail system. Today KAC supplies the military, federal agencies, and law enforcement, and every product is designed, tested, and built at its Titusville, Florida facility. Its civilian rifles and accessories meet those same standards.

The rifles KAC sells to civilians come from that same military background. We covered why KAC is worth the investment in an earlier post. This post looks at the KAC rifles, uppers, and suppressors we carry at Boss Firearms.

The KAC SR-15: A 5.56 Rifle Built to Military Standards

The SR-15 looks like an AR-15, but it's built to a much higher standard than a typical AR. Key features across the line:

• E3.2 enhanced bolt: KAC's improved round-lug bolt design spreads the stress more evenly and lasts much longer than a standard AR bolt.
• Cold hammer-forged, chrome-lined barrels with a 1:7 twist, which stabilizes a wide range of 5.56 bullet weights.
• Fully ambidextrous controls: bolt release, safety selector, magazine release, and charging handle. These are a real advantage for left-handed shooters.
• Free-floated URX M-LOK handguards with a full-length Picatinny top rail.
• Two-stage match trigger.

SR-15 Models We Carry

• SR-15 Mod 2 – 16″ Rifle: The standard full-size model, with a URX4 M-LOK handguard and Magpul MOE stock.
• SR-15 KS-4 – 16″: A newer model with KAC's URX6 handguard, a 3-prong QDC flash hider and a Magpul MOE SL-K stock.
• SR-15 Mod 2 – 14.5″ and 11.5″ CQB: Shorter, handier versions for close-quarters use.
• SR-15 KS-3 – 11.5″: A compact model with a URX6 handguard and QDC flash hider. It ships with flip-up front and rear sights.

Note: The 11.5″ and 14.5″ rifles are short-barreled rifles (SBRs) and are subject to NFA transfer requirements. Contact us with any questions.

The KAC SR-25: Proven 7.62 and 6.5 Creedmoor Performance

The SR-25 is the rifle that put KAC on the map. It's a larger-frame semi-auto known for accuracy and reliability in demanding conditions. Today the line includes both 7.62 NATO (.308 Win) and 6.5 Creedmoor models.

SR-25 Models We Carry

• SR-25 A3 – 22″, 6.5 Creedmoor: The long-range model. It has a medium-profile dimpled barrel with a 1:7.5 twist, a URX6 M-LOK handguard and a 20-round magazine. It's built for precision at distance.
• SR-25 K6 – 16″, 6.5 Creedmoor: A shorter, lighter 6.5 CM rifle with a QDC open muzzle brake and a Magpul STR stock.
• SR-25 K5 – 14.5″, 7.62 NATO: A compact .308 rifle with a hybrid light barrel profile, 1:10 twist and URX6 handguard. (This is an SBR, so NFA rules apply.)

Upper Receiver Kits: KAC Quality on Your Lower

If you already own a lower receiver, a complete KAC upper gets you most of the KAC experience for less than a full rifle. Our KAC upper kits come assembled with the barrel, handguard, bolt carrier group and charging handle.

SR-15 (5.56) Uppers:

• KS-1 – 13.7″: The civilian version of the rifle KAC built for a U.K. Special Forces contract. It has a mid-length gas system, an M-LOK handguard and an E3.2 bolt with dual ejectors.
• KS-2 – 14.5″ and KS-3 – 11.5″: Both have a URX6 M-LOK handguard, 3-prong QDC flash hider and ambidextrous charging handle.
• Mod 2 Complete Uppers – 14.5″, 16″ and 18″: KAC's standard Mod 2 configuration with the URX4 M-LOK handguard.

SR-25 (7.62 / 6.5 CM) Uppers:

• SR-25 20″ Upper: A full-length 7.62 upper for long-range builds.
• SR-25 A3 22″, 6.5 Creedmoor Upper: The same barrel and handguard as the A3 rifle, as an upper only.
• SR-25 KS7 14.5″, 6.5 Creedmoor Upper: A short, suppressor-friendly 6.5 CM upper with a dimpled hybrid barrel, QDC open brake and E3 enhanced bolt. It comes with flip-up sights.
• SR-25 K5 14.5″, 7.62 Upper Kit

Tip: The SR-25 is not a standard AR-10 pattern, so make sure your lower receiver is compatible. We sell the KAC SR-25 Lower Receiver Assembly and the SR-25 Ambi V2 Lower. Ask us if you're not sure what will fit.

The KAC M110 Sound Suppressor

The KAC 7.62 NATO M110 Sound Suppressor is the commercial version of the suppressor issued with the U.S. Army's M110 sniper system, and it's the natural choice for an SR-25.

• Caliber: 7.62 NATO / .308 Winchester
• Length: 14″
• Weight: 32 oz
• Mount: A gate-latch connector locks the suppressor to the SR-25 gas block. It requires the KAC M110 flash hider.
• Finish: Flat Dark Earth (FDE)

Because it locks to the gas block instead of threading onto the muzzle, the M110 suppressor mounts very securely. It also stays in the same position every time you put it back on, which helps your zero stay consistent.

For 5.56 Rifles: The MCQ/QDC-PRT

For an SR-15, consider the KAC MCQ/QDC-PRT 5.56 Suppressor. Its Pressure Reduction Technology reduces gas blowback and felt recoil. It's 4.43″ long, weighs 13.9 oz and fits any KAC 5.56 QDC muzzle device, including the 3-prong flash hiders that come on the KS-series rifles and uppers. It's also available as a kit with the QDC 3-prong flash hider.

Parts and Tools for KAC Owners

We also carry KAC parts to maintain and upgrade your rifle:

• E3.2 bolt assembly and ambidextrous charging handle
• URX-6 handguards (12.75″, 15″)
• SR-25 magazines (10-round, 20-round)
• URX6 tool kit, SR-15 field repair kit and barrel extension action wrench

How to Get KAC from Boss Firearms

KAC rifles and uppers are in high demand and often sell out quickly. If the model you want is on backorder, open its product page and sign up for an in-stock notification. We'll email you as soon as it's available.

Shop all Knight's Armament products at Boss Firearms

Have questions about which SR-15 or SR-25 fits your needs, or whether an upper will work with your lower? Contact Boss Firearms. We're happy to help.