E2 Armory Shows Off How Their Bolt Carrier Groups Are Machined

Luke C.
by Luke C.
E2 Armory Bolt Carrier

E2 Armory is a Florida based firearms parts manufacturer specializing in affordable AR-15 parts manufactured in house. As a former machinist, I know just how much time and effort goes into the process of producing a high-quality part that will undergo stress on a frequent basis. The E2 Armory Bolt Carrier Group is featured in their latest youtube video showing their manufacturing process.

Each of the Bolt Carrier Groups seen in the video appears to go through a batch manufacturing process whereby several pieces are machined at a time to reduce the downtime usually associated with setting a new workpiece in. In my experience, I’ve also found that this technique allows CNC machinists to spot inconsistencies early on in the machining process even before the official quality control portion has begun.

E2 Armory Bolt Carrier

The pieces being worked on in the video appear to be one of their higher-end Nickel Boron Coated Bolt carrier groups. I’ve listed the full specs for the E2 Armory NiB BCG below:

BCG Specifications

  • Bolt precision machined from 9310 alloy; carburized/case hardened & shot peened
  • HP proof testing, 100% using a high pressure M197 or SAAMI commercial equivalent, without evidence of failure
  • MPI testing after above, 100% inspection per ASTM E1444 using a standard 5 turn magnetizing coil with a current of 200 to 300 amperes. Circular and longitudinal continuous magnetization and a wet fluorescent solution shall be used. Conformance to MIL-STD-410 is required within ASTM E1444
  • ultrasonically cleaned and Nickel Boron coating
  • Markings laser engraved (HPT=High Pressure Tested, MPI=Magnetic Particle Inspection)
  • Extractor, machined 4140 Tool steel alloy, hardened with Nickel Boron coating
  • Extractor Pin, precision machined and ground AMS6440/52100 Bearing grade steel retaining pin
  • Extractor Spring, 5 coil, ASTM Grade A 228 wire stock, stress relieved, Tensile Strength of 393,000 PSI Max, 80 Durometer Per AMS-R-6855 black insert
  • Ejector, S7 shock resistant tool steel alloy, hardened, shot peened per ASTM B851/SAE AMS2430, manganese phosphate
E2 Armory Bolt Carrier
  • Ejector Spring, ASTM Grade A 228 wire stock, heat treated, stress relieved – Tensile Strength of 376,000 PSI Minimum
  • Gas Rings, Steel Corrosion Resistant Per AMS 5906 – X3
  • Carrier machined from 8620 alloy, full auto profile, heat treated, ultrasonically cleaned and Nickel Boron coating
  • Gas Key machined from 4130 chromoly steel alloy, heat treated and Nickel Boron coating
  • Socket Cap Head Screw, steel, grade 4037 per ASTM, heat treated & manganese phosphate 2x
  • Gas Key is installed with Permatex aviation gasket sealer, torqued to 55-foot pounds, pneumatically steaked and break away tests performed to spec
  • Cam Pin, precision machined 4340 chromoly steel alloy, heat treated and Nickel Boron coating
  • Firing Pin, precision machined 8740 steel alloy, heat treated, precision ground & hard chrome plate
  • Firing Pin Retaining Pin, carbon steel ASTM A510, heat treated & manganese phosphate
  • All material, components and packaging made in the USA
  • Price: $120.99

For more information and more high-quality parts from E2 Armory, you can visit their website here. As always, I am glad to see more homegrown companies taking a stake in the firearms industry.

E2 Armory Bolt Carrier
Luke C.
Luke C.

Reloader SCSA Competitor Certified Pilot Currently able to pass himself off as the second cousin twice removed of Joe Flanigan. Instagram: https://www.instagram.com/ballisticaviation/

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3 of 16 comments
  • Baron of Livonia Baron of Livonia on Feb 08, 2020

    Staked not steaked.

  • Standard Tactics Standard Tactics on Feb 08, 2020

    E2 is just the marketing front of AO Precision. E2 doesn’t make ANYTHING.

    THEY finally owned up to it after days of false marketing on numerous industry websites and blogs, and it appears this author fell for it.

    • Bpegg72 Bpegg72 on Feb 09, 2020

      @Standard Tactics Actually it was/is a company called Web Daytona doing all the marketing for E2/AOP