Optimal Bolt Carrier Group Coating

Navigating the sea of AR-15 bolt carrier group (BCG) finishes can be a daunting task, especially when you're trying to strike a balance between your needs and your budget.

The options you pick won't change the functionality of the rifle dramatically, but the coating makes a big difference when cycling the BCG and cleaning it.

Phosphate

Military rifles use phosphate as the standard for BCGs right now. It doesn't shine as much as chrome and costs less, so the military finds it useful. The phosphate finish feels rough, and some people who shoot like this because it holds oil better than other finishes.

• Pros: Affordable, durable, resistant to corrosion, mil-spec
• Cons: Rough finish necessitates more lubricant, harder to clean

Top Picks: Bravo Company (BCM) Bolt Carrier Group, Toolcraft Phosphate Bolt Carrier Group

Hard Chrome

The original AR-15 BCGs, as directed by the AR-15's creator, Eugene Stoner, were adorned with a hard chrome finish.

This finish is tough and resistant to corrosion, making it a perfect fit for the harsh conditions under which the BCG operates. Despite the rise of other finishes, chrome BCGs remain a viable option if you can get your hands on one.

• Pros: Long-lasting, resistant to corrosion, easy to clean
• Cons: Pricier than some other finishes

Top Pick: Brownells Chrome Bolt Carrier Group

Black Nitride

Also known as Melonite, Salt Bath Nitride, or simply Nitride, this finish is a product of a heat treatment process that hardens the surface. It's smooth, slick, and easy to clean, making it a popular choice among many.

• Pros: Highly durable, resistant to corrosion, smooth finish requiring less lube, easier to clean than phosphate
• Cons: Can be pricier than phosphate
  

Top Picks: Aero Precision Black Nitride BCG, Toolcraft Black Nitride BCG

Nickel Boron

Nickel Boron bolt carrier group is a modern metal finish that fights against wear and corrosion really well. It's smoother and fights corrosion better than both chrome and nitride BCGs, which makes a lot of people choose it

• Pros: Slickness, durability, resistance to corrosion
• Cons: Can be pricier than some other finishes

Top Picks: Aero Precision Nickel Boron BCG, Fail Zero Nickel Boron BCG, Toolcraft Nickel Boron BCG

Titanium Nitride

Titanium Nitride is an extremely hard ceramic material, often used in aerospace and military applications. The gold color is unique and offers a striking contrast against the matte black of the AR15.

• Pros: Smooth, hard, slick, resistant to corrosion, gold plated looks
• Cons: Pricey

Top Pick: 2A Ti BCG