Knights Armament Company SR-15 E3 CQB Mod 2 M-LOK URX 4 Upper Receiver - 11.5in Barrel

Out of stock
Knights Armament Company SR-15 E3 CQB Mod 2 M-LOK URX 4 Upper Receiver - 11.5in Barrel

The SR-15 E3 CQB Mod 2’s 11.5” chrome lined, 5.56mm NATO barrel is manufactured for military grade durability, and is free-floated inside a 10.75” URX4 handguard. An improved E3 round-lug bolt design both enhances function and increases bolt life far beyond the industry standard.  

The 5.56mm 3-Prong Flash Eliminator interferes with propellant gas combustion forward of the muzzle to significantly reduce flash signature, will not ring upon firing or when struck, and is compatible with the Knight’s line of 5.56mm QDC Signature Reduction Devices.  The SR-15 gas tube is straight, unlike Mil-Spec tubes, and the gas block is retained by a proprietary journal nut (similar to the castle nut on the buffer tube.)  The SR-15 Mod 2 is outfitted with a URX4 M-LOK rail,  KAC Micro back-up iron sights, and an extended charging handle latch.  

Compatible with SR-15 and Mil-Spec lowers, the SR-15 Mod 2 is a fully kitted out upper receiver for professionals and high-volume enthusiasts who require absolute confidence in their carbines.

Note:  The 11.5" SR-15 is an NFA item as it ships.  The muzzle device IS NOT pinned to the barrel.  You must comply with all local laws before assembling this upper receiver to a lower receiver.  We offer pinning services in house, if you choose not to go the NFA route, and we'll ship your upper to you ready to assemble to your lower.  


  • 11.5" Barrel
    • 1:7" Twist
    • Hammer Forged, Chrome Lined
    • 5.56 Caliber
  • 10.75" URX4 M-LOK Free Float Handguard
    • M-LOK Accessory Mounting
    • QD Sockets
  • Weight:  3.8 lbs
  • Knight's Proprietary E3 Bolt
  • Knight's 556QDC Flash Eliminator Muzzle Device
  • Knight's HH Buffer


    • Knight's 556QDC Flash Eliminator Muzzle Device (#30555)
    • KAC Micro Front Sight (#25654) and  KAC Folding Micro Rear SIght (#25650)
    • M-LOK 3" Rail Section - 5 Slot (#31912)
    • LMT Charging Handle with Extended Latch
More Information
Dangerous GoodsYes
Shipping RestrictionITAR/Export Restricted
FinishType III Class 2 Hardcoat Anodized
Upper BCG and Charging HandleBCG/Charging Handle Included
Upper Receiver - Stripped or CompleteComplete
Upper Receiver OperationDirect Impingement
Weapon ModelKAC SR-15
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