FailZero BCG w/ Hammer, Completely Assembled, EXO Coated, Fits M16/4, Nickel Finish FZ-M164-01-SAH

The FailZero EXO Coated Nickel Finish BCG is a fully assembled bolt carrier group engineered for shooters who demand reliability and longevity from their AR platform rifle. Built to mil-spec dimensions, this unit drops straight into most M16, M4, and AR15 upper receivers without modification—no gunsmithing or additional fitting required. The defining feature is FailZero's proprietary EXO Nickel Boron coating applied to all critical surfaces, a technology that fundamentally changes how your BCG performs under hard use.

The EXO coating delivers permanent dry lubricity, meaning you get smooth, reliable function without relying on traditional oil-based lubricants to prevent wear and corrosion. This is a genuine advantage for hunters in wet conditions, shooters running suppressed or unsuppressed setups in dusty ranges, and anyone running a piston or direct-impingement gun that generates carbon and heat. The nickel boron finish also resists corrosion far more effectively than bare steel or standard parkerization, extending the working life of a critical component that sees both heat and gas exposure on every round downrange.

Since the BCG arrives fully assembled—including the hammer—you can integrate it into your upper receiver immediately. No individual part sourcing, no assembly headaches. This makes it an ideal upgrade for shooters refreshing a tired upper, building a dedicated hunting rifle, or consolidating a parts order into fewer SKUs. The EXO coating's durability means you're investing in a component that will outlast multiple rifle builds.

Key Features

• Fully assembled and ready to install—no parts kitting required
• EXO Nickel Boron coating on all critical parts for dry-lube function
• Permanent lubricity reduces reliance on traditional gun oil
• Superior corrosion resistance compared to bare or parkerized steel
• Mil-spec compatible with standard M16, M4, and AR15 upper receivers
• Includes hammer; no additional assembly steps

Specifications

Frequently Asked Questions

Will this BCG fit my AR15 upper receiver?

Yes. This bolt carrier group is mil-spec and compatible with standard M16, M4, and AR15 upper receivers. If your upper follows mil-spec dimensions, this BCG will drop in without modification.

What does the EXO Nickel Boron coating do?

The EXO coating provides permanent dry lubricity, meaning the BCG operates smoothly without relying on traditional gun oil. It also significantly improves corrosion resistance and wear resistance, extending the life of the bolt carrier group under normal and hard use.

Do I need to assemble this BCG, or does it come ready to go?

It arrives fully assembled, including the hammer. You simply install it into your upper receiver—no parts assembly, no gunsmithing.

What's the advantage of dry lube over traditional gun oil?

Dry lube means the BCG won't attract and hold dust, carbon, and debris the way oil-based lubrication does. In dirty or wet environments, this reduces fouling and simplifies cleaning, while the EXO coating itself resists corrosion without requiring frequent re-oiling.