The Spike's Tactical ST5BG05 AR15/M4 5.56 Nickel Boron Lightweight BCG Bolt Carrier Group is an improvement over the normal Spike's Nickel Boron BCG because of the low weight which allows for a lighter rifle and more gasses to pass through when shooting the weapon. Constructed from 8620 Tool Steel (carrier) and 158 Carpenter Steel (bolt) and plated in Nickel Boron for corrosion resistance, this BCG is perfect for shooting any type of ammo without it harming the rifle. This NiB BCG is precision CNC machined in all the right places without affecting function and actually improving performance. NOTE: this BCG will fit all AR15/M4 uppers that use a 5.56 or 300BLK barrel and magazine. It will not work with any other caliber, however the bolt can be replaced with any other AR15/M4 bolt to serve the necessary barrel caliber.
Made in USA Precision CNC machined holes allow for lighter weight and more gasses to pass through.
Shrouded firing pin allows use of surplus ammo
Self-Lubricating Nickel Boron coating inside and out
Carrier laser engraved with Spike's Tactical spider logo
Forged Mil-Spec properly staked carrier key
Grade 8 Steel hardware
Bolts are shot peened are CNC machined
Full-Auto M16 profile
Extractor made of 8620 Tool Steel
Mil-Spec extractor spring, black extractor insert, Viton O-ring
Spike's Tactical Lifetime Warranty