KAK Industry
KAK Industry builds affordable, reliable AR-15 and AR-9 components for builders who want quality parts without custom-shop pricing. Impact Guns carries KAK's bolt carrier groups, lower parts kits, and completion kits — the parts that turn a stripped receiver into a finished rifle. From standard phosphate BCGs to the enhanced K-SPEC line, KAK covers the core build components most AR owners need at some point.
Read our full KAK Industry Buying Guide ↓
KAK Industry Bolt Carrier Groups: Standard vs. K-SPEC Enhanced
KAK's standard bolt carrier groups use 9310 steel construction with a chrome-lined interior and a phosphate black finish — a reliable, budget-friendly BCG for a standard build. The K-SPEC Enhanced line steps up with a 9310 steel bolt, NP3-coated bolt and cam pin for reduced friction, a dual ejector for more consistent extraction, and a down-vent gas key design. KAK also offers a K-SPEC Enhanced Low Mass version with a 7075 aluminum carrier for competition and suppressed builds where reduced reciprocating mass matters.
AR-15 Lower Parts Kits: What's Included
KAK's AR-15 lower parts kit (LPK) covers the full set of internals needed to finish a stripped lower — trigger group, springs, pins, and detents. KAK also sells the spring kit and pin-and-detent kit separately for builders replacing individual components rather than starting from scratch, plus a "missing parts kit" sized for whatever's left over after a partial build.
Upper and Carrier Completion Kits
The carrier completion kit adds the cam pin, firing pin, and retaining pin needed to finish a bolt carrier, available in standard phosphate black or chrome silver finish. The upper completion kit covers the remaining small parts needed to finish an upper receiver build.
9mm AR Bolt Carrier Groups for AR9 Builds
KAK's Enhanced 9mm bolt carrier group is nitride finished and built for AR9 pistol-caliber builds, compatible with both Colt and Glock-pattern magazine wells — a common fork in AR9 builds that determines which BCG and lower parts will fit.
Frequently Asked Questions: KAK Industry
What's the difference between a standard and K-SPEC Enhanced BCG?
The K-SPEC Enhanced line adds an NP3-coated bolt and cam pin, a dual ejector, and a down-vent gas key for smoother, more reliable cycling than KAK's standard phosphate BCG.
Do KAK lower parts kits include the trigger group?
Yes — the standard LPK includes the full trigger group along with springs, pins, and detents needed to finish a stripped lower.
Will the KAK 9mm BCG work with my AR9 build?
KAK's Enhanced 9mm BCG is compatible with both Colt and Glock-pattern magazine wells — confirm which pattern your lower uses before ordering.
Browse: AR-15 Parts
See Also: AR-15 Upper Receiver Parts • AR-15 Parts