The Rainier Arms Precision Match Grade Phosphate BCG - 5.56 Nitride 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
Nitride
Bolt:
5.56/.223
Carpenter 158 Steel
Shot Peened
Heat Treated
Nitride
Extractor:
Machined from bar
Shot Peened
Heat Treated
Maganese Phosphate
Nitride
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
Nitride
Cam Pin:
Precision machined
Heat Treated
Nitride
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
Limited Lifetime Warranty
Rainier Arms BCG offers them with a limited lifetime warranty. So if at anytime your Rainier Arms BCG breaks on your during normal use(Intentional abuse & Gas Key wear not included) they will replace it.