Knights Armament SR-15 KS-3 Upper

Knights Armament SR-15 KS-3 Upper

The Knight’s Armament SR-15 KS-3 Upper Receiver Kit distills the KS family’s reliability, modularity, and build quality into a compact, maneuverable 11.5″ package. This upper is ideal when minimal footprint and quick handling, whether in close-quarters work, transport, or as a versatile secondary upper for a multi-configuration rifle.

The KS-3 features an 11.5-inch cold-hammer-forged, chrome-lined 5.56 NATO barrel free-floated inside a URX 6 M-LOK handguard, topped with KAC’s QDC-compatible 3-Prong Flash Eliminator. As a drop-in assembly compatible with any mil-spec AR-15 / SR-15 lower receiver, the KS-3 offers a lightweight, compact foundation without sacrificing the durability and function expected of the KS line.

Compact enough for tight spaces yet fully capable when duty demands — the KS-3 balances mobility, reliability, and compatibility for builds that demand agility and modularity.

Barrel

The KS-3’s 11.5-inch cold hammer forged, chrome-lined barrel is chambered in 5.56 NATO with a 1:7 twist rate for reliable performance across a wide range of bullet weights. Its tuned gas system ensures smooth cycling and consistent function, even when suppressed. Paired with Knight’s proven E3.2 bolt design—featuring dual ejectors and an improved extractor geometry—the KS-3 maintains exceptional reliability and extended component life under high round counts or adverse conditions.

Handgaurd

The URX 6 handguard offers a rigid, self-indexing design with a full-length 12 o’clock MIL-STD 1913 rail and seven sides of M-LOK mounting slots. It aligns precisely with the upper receiver via an internal tab-and-slot system and secures with a retention nut that provides exceptional resistance to shift or impact. The streamlined profile eliminates external fasteners and snag points while maintaining perfect zero retention for mounted accessories.

Flash Hider

The KAC 5.56mm 3-Prong Flash Hider disrupts propellant gas combustion at the muzzle, greatly reducing visible flash. Its three-prong design eliminates ringing during firing and remains fully compatible with KAC’s 5.56mm QDC suppressors.

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