AR-15/M16/M4 – Bolt Assembly – EXO Nickel Boron – Complete

Fail Zero

$85.00

More on the way!

AR-15/M16/M4 – Bolt Assembly – EXO Nickel Boron – Complete


PLEASE DOUBLE CHECK DETAILS AND FITMENT BEFORE PURCHASE.

FailZero built this complete EXO bolt assembly for mil-spec AR-15, M16, and M4 carrier systems that need a coated replacement bolt setup without buying a whole carrier group. It arrives assembled and uses the company’s nickel boron treatment to keep friction down, cleanup easier, and wear resistance up.

This is not a full BCG. It is the bolt assembly only. That sounds obvious until somebody orders the wrong thing and learns reading is important the hard way.


Fitment

  • Compatible with most mil-spec AR-15, M16, and M4 carriers
  • Complete bolt assembly
  • For common 5.56 NATO and .223 Remington pattern use

Does NOT fit

  • Not a complete bolt carrier group
  • Do not assume compatibility with proprietary carrier designs

What it does

This replaces the bolt portion of the operating system while keeping the carrier you already have. It is useful for repairs, refreshes, or keeping a spare ready without buying the whole carrier and gas key assembly again.


Why it’s worth it

Sometimes the right move is not buying the whole damn BCG. If the carrier is fine and the bolt is what needs help, this gives you a cleaner, coated replacement route from a known brand.


Specs

  • Brand: FailZero
  • Product Type: Complete bolt assembly
  • Finish: EXO nickel boron
  • Compatibility: Most mil-spec AR-15, M16, and M4 carriers
  • Use Case: Replacement or spare bolt assembly

What’s included

  • 1 complete bolt assembly

Tools needed

Basic bolt and carrier service tools may be helpful depending on the host setup and inspection needs.


Install notes

Verify headspace and extractor function before serious use. A replacement bolt should be treated like a real component change, not a blind parts swap.


Verify before you buy

Verify you need the bolt assembly only and not a full BCG. Verify to prevent returns: this part is only one piece of the larger system.


⚠ Install & Compatibility Disclaimer

Installation should be performed by a qualified armorer or gunsmith. Improper installation, modification, or use may affect firearm safety and reliability. Buyer is responsible for verifying compatibility, performing proper function testing, and ensuring safe operation.

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