5.56 Complete AR15 Upper Receiver- 10.3" MIL Clone Barrel, 9" MLOK, Full Chrome K-SPEC BCG

This upper is built on clone barrels we fufilled contracts for the US Army

These barrels are designed to function with a standard 3 oz carbine buffer and full power ammo

• Barrel length- 10.3"

• Gas system- Carbine Length

• Gas port size- .0705- Crane Spec

• Threads- 1/2x28

• Grenade launcher flats

• Finish- chrome lined phosphate 

• Twist- 1:7

• Material- 41V50 chrome moly vanadium 

• Barrel dimpled for gas block set screws

• Marked for caliber, twist, cage code, production date, magnetic particle inspection, and the chrome line facility used

• Profile- SOCOM HEAVY

• Muzzle device- SAW Flash Hider 

• Extension- M4

• Gas Block- Low profile .750 phosphate finish

• Charging Handle- Milspec with Enhanced Large Billet Latch

• Upper Receiver- Forged 7075 T6 Aluminum, Precision Machined to M16/M4 Spec

• Handguard- 9" High Quality 6061 T6 Material Mlok with Proprietary Clamping System and Heavy-Duty Barrel Nut

BCG- Choose between down vent or side vent version 

The K-SPEC BCG combines multiple key features focused on increasing the reliability of your AR15 style firearm no matter if you are running suppressed or unsuppressed, and regardless of conditions.  The K-SPEC is a truly plug and play BCG that will accommodate whatever configuration your mission requires.

For those running suppressed, the K-SPEC requires no additional tuning or tweaking of the gas or recoil systems to run reliably.  Like all KAK BCGs, the K-SPEC is machined to the M16 full auto profile.

Reduced Peak DB Report

When used in conjunction with a silencer, the gas redirect produces a quieter report

See testing results here- Down Vent vs Side Vent DB reduction testing

Slotted Angled Carrier Rails

For enhanced functionality in adverse and rugged conditions such as sand, mud, dirt, and grime. These rail cuts are designed for debris disbursement, resulting in ultra-high functionality in the toughest conditions, including suppressor fouling and foreign contaminates. Strategically located angle cuts in the rails result in fouling and debris being moved into noncritical areas that are not in contact with the receiver and do not affect the function of the firearm. aka sandcutter

Downward Gas Vents

In an effort to reduce the amount of debris and gas vented towards the shooters face, the two standard gas relief ports have been relocated from the ejection port side of the K-SPEC carrier and placed underneath, in the magazine feed lip channels.  Two additional emergency relief ports have also been added to the bottom of the carrier to mitigate structural damage in the event of a case head separation.  Testing has shown that venting the gasses through the magazine well has no negative impact on the feeding or function of the magazine nor ammunition, and any added heat is negligible. 

Dual ejectors

The K-SPEC dual ejector system uses mil-spec ejectors and springs that require no proprietary parts.  Ejector holes are centered on the lugs to avoid any reduction in strength of the bolt.  The dual ejector system increases the ejection reliability and adds consistency to the ejection pattern. KAK Industry has been manufacturing dual ejector bolts for the AR10/LR308 platform for over a decade and has used that experience to create a durable and reliable dual ejector system for the AR15 platform.

• Designed to function reliably in the toughest conditions
• Optimized for both Suppressed and Un-suppressed use, All uses – All Conditions
• Dual Ejectors for enhanced reliability
• Angled Carrier Rail Cuts for flawless function in adverse conditions and prolonged suppressed use
• Downward Gas Ports to reduce gas blowback to shooter
• Full Auto Profile
• Permatex added between Gas Key and Carrier Mating Surface
• Carrier- 8620 steel, outside rails, bolt runs, and gas bores ground to .0002 tolerances, Chrome finish
• Bolt- 9310 steel, outside diameters ground to .0002 tolerances, MPI test, Chrome finish
• Firing Pin- 8740 steel, Swiss turned, heat treated, precision ground, chrome plated
• Cam Pin – 4140 steel, Swiss turned, heat treated, Chrome finish
• Extractor- 4140 steel, fully machined, Phosphate coated
• Extractor pin- S7 tool steel, ground, heat treated
• Ejector- S7 tool steel, ground, heat treated
• Gas key – 4130 steel, heat treated, Chrome finish, secured with T25 torx fasteners, torqued to spec, staked with  hydraulic staking machine

  Machined in house and assembled using only the finest steels and components. 

KAK Industry takes pride in producing some of the finest Mil-Spec/ Enhanced AR15 bolt carrier groups available, made 100% in house at our MO facility using Doosan machining centers, Tsugami Swiss turning, and the latest in FANUC robotics combined into an automated cell giving us lights out production capability.  In house automated CMM Inspection processes ensure consistent quality. 

  Fully Made In House From KAK Industry Produced Blanks

All Barrels Are Air Gauge Inspected for Correct Bore Size & Tolerances, completed Barrels are Inspected for Proper Headspace using Calibrated Gauging.