When it comes to your AR-15's bolt carrier group, reliability is key; that's what you get with RISE Armament's advanced Nickel Boron Bolt-Carrier Group (BCG): reliability.
At RISE, we manufacture each of our bolt carrier groups with precision. We also individually inspect each one to ensure high-level performance. Our signature AR-15 Bolt Carrier Group is available in two finishes. The first finish is a black nitride. However, the one we're focusing on here is our nickel boron coating, which reduces friction and also improves overall performance.
So why is nickel boron so great? For that, here's a little science. Nickel boron (NiB) is a columnar-formed compound. It's about 95 percent nickel and 5 percent boron. Due to its formation, it reduces contact points between surfaces. However, it still provides an additional layer of hardness to the steel. Because of the reduced surface contact—given only the rounded ends of the NiB column's touch—it acts almost like a lubricant.
What does this all mean as it relates to our nickel boron bolt carrier group? Compared to standard chrome, nickel boron provides more resistance to wear and corrosion; that's important because it means you get a bolt carrier group built to last much longer than anything else you'll find on the market. Longevity is exactly what you want from your bolt carrier group. The end result from our work is an 11.6-ounce bolt carrier group that we've tested every possible way to withstand whatever you throw at it. In case you were wondering, here's a look at exactly what makes up our nickel boron BCG.
- Bolt: 9310 MPI tested
- Carrier: 8620 tool steel heat treated and case hardened
- Gas key: tool steel - grade 8 hardened fasteners and staked properly
- Cam pin: 4140 steel
- Extractor: tool steel – shot peened