Knight's Armament SR-15 KS-4 5.56mm NATO, 16 in Barrel, URX 3.1 Free-Float, KAC Micro Sights, Magpul SL-K Stock
This Knight's Armament SR-15 KS-4 is a 5.56mm NATO semi-automatic rifle built on the AR-15 platform, marked "Stoner Rifle" with the KAC crest and manufactured in Titusville, Florida. It features a 16-inch threaded barrel with a three-prong flash hider, a KAC URX 3.1 free-float handguard with full-length top Picatinny rail, and KAC micro folding iron sights installed. The rifle includes Magpul furniture and ambidextrous controls, combining KAC build quality with practical, duty-focused features.
Condition
Overall Condition: Very good condition, showing only light, superficial signs of prior handling or use.
Bore Condition: Excellent - Clean, mirror finish, no signs of wear.
Bore Rifling: Excellent Rifling - Sharp lands and grooves.
Specific Condition Notes: Minor handling marks are present on exterior surfaces. The bore appears bright and clean on inspection. Please review the photos for a close look at the finish and markings.
What's Included
- Knight's Armament SR-15 KS-4 5.56mm rifle
- Two 30-round Magpul PMAG polymer magazines for 5.56x45
- KAC micro folding front sight (installed)
- KAC micro folding rear sight (installed)
- KAC short 1913 Picatinny rail segment at 6 o'clock on the handguard (installed)
- KAC dual QD sling mount on the handguard (installed)
- Polymer rail/heat-shield panels on the handguard (installed)
The receiver is marked "KNIGHT'S MFG CO., TITUSVILLE, FL USA" and "SR-15," with the right side marked "5.56mm KS-4." The magwell carries the "Stoner Rifle" legend alongside the KAC crest. These factory rollmarks clearly identify the rifle as a KS-4 variant within the SR-15 series.
The 16-inch barrel is threaded and fitted with a three-prong flash hider. The action is semi-automatic, direct impingement, chambered in 5.56mm NATO with a capacity of 30+1. The rifle retains standard AR features including a forward assist, ejection-port cover, shell deflector, and charging handle.
A KAC URX 3.1 free-float aluminum handguard anchors the front end, providing a full-length 12 o'clock Picatinny rail and oval accessory slots. Installed accessories include a KAC short 1913 rail segment at 6 o'clock, KAC micro folding front and rear sights, and polymer rail/heat-shield panels that enhance handling.
Ergonomics and controls include an ambidextrous safety selector with SAFE/FIRE legends on both sides and a right-side bolt release. The rifle is outfitted with a Magpul MOE SL-K collapsible stock in black and a Magpul MOE K2 pistol grip in FDE. The receiver and handguard wear a matte black anodized finish.