AIM AR/M16 H4 .223/5.56/.300 BLACKOUT 9310 MPI Bolt Carrier Group


$109.95 Quantity:  

     Add To Wish List      

AIM H4 AR/M16 5.56/.223/.300 BLACKOUT complete Bolt Carrier Groups. Features UCT's exclusive Nickel Boron EXO Technology coating and H&M's BLACKNITRIDE finishes. A newly designed carrier reduces the surface area contact between the carrier and receiver walls. This improves performance and reliability as it reduces drag and creates "debris" channels to reduce malfunctions. Features 9310 Bolt Material; 8620 carrier; Properly staked machined billet gas key hardened to USGI specifications fastened with Hardened Grade 8 Fasteners; Shot peened MPI (Magnetic Particle Inspected) Bolt. Extractor insert installed. Proudly made in the USA with a Lifetime Warranty.

WARNING: This product can expose you to chemicals including nickel & chromium, which is known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to -

3 to 9 $109.95
10 to 34 $109.95
35 or more $109.95

EXO Technology creates a competitive advantage for all kinds of components, because treated parts run dramatically longer and more accurately with less maintenance. Further, EXO greatly enhances heat dissipation, so treated products run far cooler than non-treated parts.
The EXO process is permanent, lasting for the entire lifespan of treated parts. A patented, nodular nickel-boron (NiB) surface treatment, EXO nucleates on the surface atoms of metals, becoming part of the metal rather than merely applied to the outside. In addition, the treated surface becomes harder than the substrate itself, eliminating the cost, weight and degradation problems of conventional hardened metals.
EXO Technology is featured in firearms, weapons and support systems used by the U.S. military and law enforcement and security agencies. EXO Technology is appropriate for virtually any application where reduced friction, extended service life, enhanced performance and lower maintenance are desirable.

BLACKNITRIDE™, or Ferritic Nitrocarburizing, is the thermochemical that simultaneously diffuses nitrogen and carbon into the surface of ferrous metals. During the process, a two-part surface layer is formed, an outer iron nitride layer with a nitrogen diffusion layer below it. During this treatment, nitrogen and carbon are absorbed by and diffused into the surface of the metal. Reproducible and uniform layers with a predetermined thickness will be formed on all areas of the metal. The result of this process is markedly improved surface properties on ferrous metal parts while maintaining dimensional and shape stability.
Metal components treated with BLACKNITRIDE™ have increased wear-resistance, fatigue strength, corrosion resistance, lubricity and cosmetic appeal. Often replacing the more expensive processes of hard chrome or nickel plating, BLACKNITRIDE™ gives better corrosion protection at equivalent or lower costs. Additionally, BLACKNITRIDE™ is commonly used as an alternative to high temperature conventional heat treatments such as carburizing and carbonitriding.

The requirements for assembly of our Bolt Carrier Groups are much higher than most. Before assembling the gas key to the carrier, permatex NO.3D aviation is applied to form-a-gasket around the gas hole (per MIL-SPEC). Then Grade-8 hardware is used to attach the gas key, followed by properly staking per spec. When installing the extractor to the bolt, a crane-o-ring is inserted with the spring to insure proper ejection. Then high temperature grease is applied to the gas rings before inserting the bolt into the carrier, which allows for much smoother operation. These BCGs are inspected to the highest of standards, to insure a high quality product that is 100% reliable for our customer… PROUDLY MADE IN THE USA!

  • M16 style (Auto)
  • Machined from 8620 tool steel
  • Heat treated to military specifications
  • Machined from 9310 tool steel
  • Heat treated to military specifications
  • Shot Peened
  • Ground to meet military required tolerances
  • MPI (Mag Particle Inspected)
Gas Key
  • Machined BILLET 4140
  • Heat treated to military specifications
  • Machined from 4140
  • Heat treated to military specifications
  • Shot peened
Firing Pin
  • Machined from 8640 tool steel
  • Heat treated to military specifications
  • Ground to meet military required tolerances
  • Coated with .0002”-.0003” of hard chrome per MIL-STD-171
Cam Pin
  • Machined from 4340
  • Quench and temper heat treat
  • Ground to meet military required tolerances


You must be logged in to use this feature. LOGIN

©2018 AimSurplus, LLC, all rights reserved. Terms & Conditions. 1-888-748-5252 EMail: '' An IMX Solutions Inc. EOS360 Extend Solution.