The S in SBCG stands for Secure Staking, Slick Side. SBCG carrier has a series of serrations or dimples to aid in closing an out of battery bolt on upper receivers without a forward assist. The carrier is still cut for the pawl of a forward assist notches and is fully compatible with slick or standard upper receivers. The serrations on the carrier offer texture in order to act as a field expedient forward assist.

The Secure Staking is achieved via the OCKS (Optimized Carrier Key Screws). The knurled OCKS get much better bite from proper staking, and require 55-100 inch pounds of torque in order break loose. Essentially -- this carrier key won't come loose under any sort of firing schedule. A flyaway carrier key (from not being properly staked) can cause a catastrophic failure in an AR-15. Carrier keys can still fail, cracking or debris getting lodged in the key -- it is nice to have the option to replace a carrier key and not the entire bolt carrier itself. So this unit is still user serviceable unlike one-piece carriers.

All SBCGs are test fired with 5 rounds of XM193 before shipping.