Today we’ll give you an in depth Aero Precision Pro BCG Review. This bolt carrier group features a lot of upgrades from their normal black nitride and phosphate finish versions.

Tell me more about Aero Precision 5.56 AR15 BCG options

We did a brief breakdown of all the Aero Precision BCG options. We discussed Nickel Boron, Nitride, and Phosphate finished bolts.

It’s important for builders to select the best BCG for both budget and reliability.

The Aero Precision Pro 5.56 BCG is Aero Precision’s most expensive BCG. But it comes with some special features.

Why go Pro?

The Aero Precision PRO 5.56 Bolt Carrier Group is built to meet the harsh demands of the most extreme situations. Every component and manufacturing process in making the PRO 5.56 Bolt Carrier Group was specially chosen to give it the most reliable service life of the bolt carrier group.

AR15 5.56 PRO Series Bolt Carrier Group - Black Nitride

Special features of the Aero Precision pro 5.56 BCG


The bolt is the most important part of the BCG. It’s made from 9310 steel and is run through a proprietary flash nitride process. This helps ensure proper heat treatment of the bolt. When a bolt is properly heat treated, 9310 steel gives best in class strength and durability when compared to other metals.

The cam pin channel is counter bored, which eliminates the need for swaging. Swaging is industry standard, but this process is more stress on the bolt during manufacturing. Giving a superior bolt tolerance and strength.

  • Machined from 9310 steel
  • Shot peened
  • MPI (magnetic particle) tested
  • Proper heat treatment ensured via proprietary flash-nitriding process

Cam Pin

Each PRO cam pin on the BCG is percisely ground after heat treatment to tight tolerances and given a nitride finish.

The cam pin features an indexing mark on one side of the cam pin face. Cam pins traditionally wear more on one side when installed inconsistently. This will cause excessive wear over time.

When the pin becomes “loose”, this will make excessive wear on the bolt – shortening its overall life.

The indexing mark allows for consistent installation during maintenance. Which reduces wear on the cam pin and bolt over time – this will help extend overall service life.

  • Machined from 4140 steel
  • Precision ground after heat treatment
  • Engraved indexing mark
  • Nitride finish


The extractor has a phosphate finish. The extractor is actually one of the few places where it is beneficial to have a “rougher” finish. It gives a more positive engagement with the case when pulling a casing out of the chamber.

  • Machined from 4140 steel
  • Heat treated
  • Shot peened
  • Phosphate finish


Each PRO BCG is M16 cut and has a nitride finish.

Internal critical surfaces are precision ground to precise tolerances to ensure optimal gas efficiency. The same machining tolerances are used for the carrier rails, which gives a smooth fit and function from the start.

  • Machined from 8620 steel
  • M16 Cut Carrier
  • Nitride Finish
  • Critical surfaces precision ground for optimal gas efficiency and reliability

Gas Key

  • Machined from hardened 4140 steel
  • Torqued to spec with grade 8 hex fasteners
  • Properly staked to mil-spec
  • Nitride finish


  • Machined from S7 tool steel

Firing Pin

  • Ground from 8640 steel
  • Nitride Finish

Why is the BCG so important?

Imagine the upper and lower receiver are a human body. The human body cannot operate with the heart, some organs, arteries, veins, etc. Think about the BCG (you could add other parts here too, buffer tube, charging handle, etc) as the vital organs and blood pathways.

Bolt Carrier Groups

Much like a body when a heart fails – when the BCG fails, so does the entire rifle. You cannot fire the rifle without a properly functioning BCG.

Have rifles been shot with crack components? Sure. But the PRO’s special features make it a great choice for hard shooting.

Which BCG is right for me?

So there’s the PRO, Nickel Boron, Phosphate, and Nitride finish BCG’s. Which one is best for you?

Shooting frequency matters

Are you a weekend shooter or a tier one operator? If you’re putting thousands of rounds through each year, go with a specially treated bolt like the Aero Precision Pro 5.56 BCG.

Do you shoot for competition? You might be good with a Nitride Finish. Hate cleaning your rifle? Check out the Nickel Boron finish BCG.

Phosphate would be great for a once a month or couple times a year shooter.

Replacement parts vs whole new BCG

Depending on how often you shoot – your BCG will eventually fail. The firing pin may break. The bolt may crack. A bunch of things might happen.

It may be cheaper to replace a single part versus a whole new BCG.

Does Aero make a good BCG?

Aero Precision makes Mil-Spec or higher quality parts. The Aero Pro BCG is no exception.

The Pro BCG utilized so many processes to make it the ultimate BCG when compared to other company’s BCG’s.

Does Aero Precision make their own BCG?

Aero Precision has a huge manufacturing plant where they mill all their parts.

Is The Nickel Boron BCG still the best?

We don’t think so in this review. Running the Aero Pro BCG has shown us that superior quality and durability matter most as compared to an easy weapons cleaning.

Join Worth Firearms Mailing List

Weekly emails about promotions, how to's, and gear reviews. Easy to unsubscribe!

Error: Contact form not found.

Store Hours

Mon - Sat: Available by Appointment Only
Sunday: Closed

Want to pick up your order in Keller, TX? Contact us to set an appointment!

Worth Firearms © 2022. All rights reserved.