When we last told you about the SureFire Advanced Rifle Operating Core and Optimized Bolt Carrier we weren’t sure when it would be available commercially. But SureFire had the OBC on display at SHOT Show and told us the first run are just finishing up production.
While the entire AROC consists of an enhanced Bolt Carrier Group, Barrel Extension, Buffer and Spring, the OBC is a drop-in Bolt Carrier Group which fits both piston and DI ARs.
The OBC features an internal weight which is spring loaded in both directions. This, along with the other elements, combine to offer additional travel time. When the Bolt is at the end of its stroke while using a Mil-Spec BCG, it takes 28 milliseconds for the bolt to travel back into battery. With the OBC, it’s 38 milliseconds. That slight difference is signifigant, especially when firing full auto or suppressed, or both. You’ll also notice that the gas key has a single screw. It comes with a 2 oz H2S buffer and an included Action Spring offers additional tension.
