$20 OFF! $319.99 Now $299.99



The Rainier Arms Precision Match Grade Nickel Boron BCG - 5.56 is machined and finished to a higher standard to meet and exceed all Mil Spec. It is machined using the most precise equipment in the industry. The bolts are MPI/HP tested & Marked to give you ultimate confidence in your weapon system.

Carrier:
  • Full Auto Carrier
  • SAE 8620
  • Heat Treated
  • Nickel Boron Plated


Bolt:
  • 5.56/.223
  • Carpenter 158 Steel
  • Shot Peened
  • Heat Treated
  • Nickel Boron Plated


Extractor:
  • Machined from bar
  • Shot Peened
  • Heat Treated
  • Maganese Phosphate


Extractor Spring:
  • Chrome Silicone for Longer Life
  • Black Insert as per current Mil-Spec
  • "O" Ring is high temp resistant dark brown


Extractor Retaining Pin:
  • Precision Machined
  • Precision ground to diameter
  • Precision ground to length
  • Heat Treated


Firing Pin:
  • Machined and then precision ground for accuracy
  • Heat Treated


Gas Key Bolt:
  • Precision manufactured in house with extra deep knurling
  • Grade 8
  • 1200 degree locking patch is factory applied to threads to help insure long lasting tightness


Gas key:
  • Hard Chrome lined gas tube as per Mil-Spec
  • Bolts installed to proper torque
  • Staking on both sides of both bolts


Cam Pin:
  • Precision machined
  • Heat Treated
  • Nickel Boron Plated
  • Firing Pin Retaining Pin:
  • Precision bent
  • Precision cut to length
  • Heat Treated


Gas Rings:
  • Stainless Steel per Mil-Spec


Ejector:
  • Precision machined
  • Heat Treated


Ejector Spring:
  • Chrome Silicone
  • Precision ground ends


Ejector Retaining Pin:
  • Precision cut to length
  • Hard Chrome Plated


$299.99