Arm or Ally AR15 / M16 5.56 NATO Bolt Carrier Group – Black Nitride


5.56 NATO / .223 Rem, Black Nitride, Shot Peened, MPI inspected
SKU: AOA556BCG Categories: , , Tags: , ,

M16 / AR15 5.56 NATO Bolt Carrier Group - Black Nitride

100% Made in America

Arm or Ally M16 / AR15 Bolt Carrier groups in 5.56 NATO are precision ground, properly heat treated, full-Auto M16 BCG, manufactured using the finest U.S sourced raw materials available. The Black Nitride finish vastly increases the hardness of the steel, prevents corrosion, is highly resistant to wear, will not flake (it's not a coating, it's a bond), and has increased lubricity when compared to a phosphate finished BCG.  The Bolt Carrier Group is the heart of your rifle, and if you want to upgrade the reliability and functionality of your rifle, this is a great part to replace way to do it!

Since 2015, Arm or Ally has handled hundreds of thousands of bolt carrier groups and was the leading dealer of the Toolcraft BCG.  Trust us, when we say "we know bolt carrier groups"!  We have chosen specific manufacturers for each component of our BCG due to their high-quality parts, and attention to detail. For this particular BCG, we leave off the fancy logos and packaging and deliver you a best-in-class BCG for a very attractive price.

Bolt Specs
Material 9310 Steel
Extractor 4140 Billet Steel, O-Ring, Phosphate
Cam Pin 8620 Steel
Firing Pin 17-4-H-900 Stainless Steel
Finish Black Nitride+
Other MPI, Shot Peened, Heat Treated
Carrier Specs
Material 8620 Steel
Type M16 Full-Auto
Gas Key 4140 Billet Steel; Grade 8 Fastners
Finish Precision Ground; Black Nitride+
Other Heat Treated

What is the Arm or Ally Brand?

Arm or Ally branded products are manufactured in the same facilities and to the same standards as many popular, high-end brands.  Our promise to you is a high-quality product at a more affordable price. 100% American made products, backed by the same defect-free warranty as every other product we offer.

Product Information
SKU AOA100615C | AOA100615-158
Manufacturer Leading U.S. Manufacturer
100% American Made Yes
Caliber 5.56 NATO | 223 Rem
Finish Black Nitride
Platform AR15
Compatability Works with standard Milspec AR15 components
Weight 12oz

Arm or Ally is a stocking dealer for all Faxon Firearms, Ballistic Advantage, HOLOSUN, Toolcraft, Elftmann Tactical, Timney, CMC Triggers, HIPERFIRE and named the #1 Overall E-Commerce Dealer for Aero Precision Products in 2020!  See our growing inventory of AR Parts, and Reloading Components.

Weight 15 oz
Dimensions 8 × 4 × 2 in

Arm or Ally

Part Type

Bolt Carrier Group, Upper Receiver Parts




5.56 NATO

Coating Type

Black Nitride

Select Type

9310 Bolt, Carpenter 158

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