Knights Armament Sr-25 K3 7.62 Nato/.308 16'' Bbl Assembled Upper Rcvr Black

The Knights Armament SR-25 K3 assembled upper receiver in 7.62 NATO/.308 is a semi-automatic precision rifle platform purpose-built for mid-range accuracy and rapid follow-up shots. This 16-inch barreled upper brings the battle-proven SR-25 lineage—derived from the U.S. military's M110K3—into a compact, field-friendly form factor ideal for hunters, precision shooters, and tactical practitioners who demand reliability in variable conditions. Whether you're ringing steel at 300 yards, hunting medium to large game, or building a versatile rifle system, the K3 upper delivers the accuracy and handling characteristics that have made the SR-25 a professional favorite.

Built around a high-pressure dual-ejector bolt, this upper functions reliably whether you're running suppressed or unsuppressed ammunition in adverse conditions—mud, sand, or sustained fire—while the extended bolt service life means you'll get more rounds downrange before maintenance. The 16-inch 416R stainless steel barrel features KAC's signature 5R rifling and a 1:10-inch twist rate optimized for 7.62 NATO ballistics; the dimpled design enhances cooling and aesthetic appeal. The included 7.62mm open brake tames recoil, and the unit accepts KAC QDC Signature Reduction Devices for suppressor integration, opening doors to quieter shooting without sacrificing velocity or accuracy.

Ergonomics matter in precision shooting, and the K3 delivers. Fully ambidextrous controls—charging handle, safety, and bolt release—work flawlessly for both right- and left-handed shooters. The SR-25 K3 ships with KAC's URX6 handguard, a battle-hardened tube designed to stay put under recoil and rough handling; seven sides of M-LOK mounting slots plus a full-length MILSTD-1913 top rail give you flexibility to mount optics, lights, and accessories exactly where you need them. The drop-in two-stage trigger breaks clean and aids precision marksmanship without requiring gunsmithing.

This is an assembled upper receiver—pair it with a compatible lower receiver, buttstock, and charging handle to complete your build, or integrate it into an existing system. Built to exacting KAC standards and backed by real-world military and law enforcement use, the SR-25 K3 upper is an investment in accuracy and dependability.

Key Features

• High-pressure dual-ejector bolt for reliable function in suppressed and adverse conditions
• 416R stainless steel barrel with 5R rifling and 1:10-inch twist
• Fully ambidextrous controls—charging handle, safety, and bolt release
• URX6 handguard with seven M-LOK slots and continuous MILSTD-1913 top rail
• Drop-in two-stage trigger for precision shooting
• 7.62mm open brake; compatible with KAC 7.62mm QDC suppressors
• 16-inch barrel for mid-range accuracy and compact handling

Specifications

Frequently Asked Questions

What lower receiver does the SR-25 K3 upper fit?

This is an assembled upper receiver designed for use with a compatible 7.62 NATO AR10-pattern lower receiver. Knights Armament manufactures dedicated lowers for the SR-25 platform, but other quality AR10 lowers may work; verify compatibility with your intended lower before assembly.

Can I run this upper suppressed?

Yes. The dual-ejector bolt is specifically engineered for reliable suppressed and unsuppressed operation. The 7.62mm open brake is compatible with KAC 7.62mm QDC Signature Reduction Devices for seamless suppressor integration.

What comes in the box?

You receive the assembled upper receiver with barrel, bolt carrier group, handguard, trigger, charging handle, and muzzle device. You will need to source a compatible lower receiver, buffer tube assembly, and buttstock to complete the rifle.

Is the SR-25 K3 good for hunting?

The 16-inch barrel and mid-range optimized design make the K3 a practical platform for hunting medium to large game at typical field distances. The reliable action, precision trigger, and rail system for optic mounting support hunting applications where accuracy and reliability matter.