This bolt carrier group for AR-15 style rifles meets or exceeds mil-spec. It has a black nitride finish which not only resists corrosion but reduces the need for lubricants. The carrier is case hardened 8620 steel. The bolt is true mil-spec dimensions and made of case hardened 9310 steel. It has been magnetic particle tested and undergone a high pressure test The 4130 steel gas key is properly staked.

Specifications and Features
.223 Remington/5.56 NATO/.300 AAC Blackout
Bolt Carrier Group Material Case Hardened 8620
Steel Finish Black Nitride
This advanced low friction coating minimizes the need for lubricants
Gas Key 4130 Steel attached with Grade 8 hardware and properly staked into a milled "valley" to ensure proper positioning
Cam Pin Hardened 4340
Mil Spec firing pin made of 8740 steel, center-less ground and Hard Chrome coated
The Bolt is "true" Mil Spec dimension and external surfaces are CNC ground after heat treat for a precision fit
Bolt Material Case Hardened 9310 Steel
All Bolt components Black Nitride
Extractor: 4340 Steel Mil Spec
Extractor Spring & O-Ring Combination
MPI: Magnetic Particle Inspected
HPT: High Pressure Test
Made in USA