KAK AR15 BCG – 5.56, C158 Bolt, Chrome Lined Phosphate
Not Yet Rated | Write the First Review SKU: 222-KAK-425-3312-003
MFG#: 425-3312-003

The AR15 Bolt Carrier Group (BCG) from KAK Industry combines a C158 bolt, chrome-lined phosphate finish, and an M16 full auto profile for unmatched durability. Built to Mil-Spec standards, this unmarked carrier group is designed for shooters who want a reliable, high-quality BCG that runs in both training and defensive applications. With a rugged phosphate exterior and a slick chrome lining, it’s engineered to deliver long-lasting performance in your 5.56 NATO AR-15 rifle.

Key Features

• C158 Bolt – Made from Carpenter 158 steel, heat treated and shot peened for maximum strength

• Chrome-Lined Phosphate Finish – Traditional phosphate exterior for toughness with a chrome interior for smooth cycling and easy cleaning

• Full Auto Profile – Machined to M16 specs for added strength and reliability

• Unmarked Design – No manufacturer roll marks, ideal for clean builds or professional setups

• Mil-Spec Tested – Magnetic Particle Inspected (MPI) for integrity and long-term durability

• Compatibility – Works with all Mil-Spec AR-15 rifles chambered in 5.56 NATO and .223 Remington

Why Choose a C158 Bolt AR15 BCG?

Carpenter 158 steel is the gold standard for AR15 bolts, used in Mil-Spec rifles for decades. This material, combined with proper heat treatment and MPI testing, provides superior strength and resistance to cracking under heavy use.

Chrome-Lined Phosphate vs Standard Finishes

This BCG features a chrome-lined interior for smooth operation and corrosion resistance, paired with a phosphate exterior that retains oil and offers proven field durability. It’s the best of both worlds — slick performance and rugged Mil-Spec toughness.

Ideal for Builders & Professionals

With an unmarked carrier body, this BCG is perfect for custom AR15 builds or professional rifles where a clean look is preferred. Combined with its Mil-Spec pedigree, it’s ready for duty, competition, or personal defense.

FAQ – AR15 C158 Chrome Phosphate BCG

Q: What calibers is this AR15 BCG compatible with?
A: It’s designed for 5.56 NATO AR-15 rifles, and also works with .223 Remington.

Q: What makes a C158 bolt better than other steels?
A: Carpenter 158 steel is the Mil-Spec standard, offering proven reliability and durability under high round counts.

Q: Why choose a chrome-lined phosphate BCG?
A: Phosphate provides a tough, oil-retaining exterior while chrome reduces friction and resists corrosion inside the carrier.

Q: Is this BCG full auto rated?
A: Yes. It’s machined to the M16 full auto profile, making it stronger and more reliable than semi-auto carriers.

Q: What does “unmarked” mean?
A: The carrier body has no roll marks or engravings, giving it a clean look and making it ideal for custom rifle builds.

Q: Is the bolt MPI tested?
A: Yes. Each bolt is Magnetic Particle Inspected (MPI) to confirm strength and quality.

Final Thoughts

The AR15 BCG – 5.56, C158 Bolt, Chrome-Lined Phosphate, Unmarked offers Mil-Spec reliability with premium materials and finishes. With its full auto profile, C158 bolt, and chrome phosphate design, this carrier group is a dependable upgrade for any AR-15 rifle.

👉 Add the KAK AR15 C158 Chrome Phosphate BCG to your build today and experience proven strength and smooth cycling.