Black River MFG ACX 1913 Collapsible Stabilizing Brace

The Black River MFG ACX 1913 Collapsible Brace is the pistol-configured variant of the ACX 1913 stock. The chassis, adjustment mechanism, ambidextrous tail hook, and 9-position collapse range are identical to the stock; the only difference is a soft stabilizing cuff in place of the rifle buttplate, which makes the assembly legal on a pistol-configured host without an SBR.

Construction is all-aluminum on the load-bearing parts, with the soft cuff added at the rear. The LOP collapses across 9 positions, the tail hook is ambidextrous, and the QD sling socket runs through the tail. The brace mounts to any 1913 Picatinny rear interface: Sig MPX/MCX, Stribog with factory 1913 adapter, Scorpion with HBI 1913 adapter, Kuna, B&T APC9 and GHM9, AR pistols with 1913 endplates.

Pick the ACX brace over the stock when the host is a pistol and you want to stay pistol-configured. Pick the stock when you have an SBR. Pricing is roughly $30 higher than the stock variant due to the brace cuff; available colors mirror the stock SKUs (Black, FDE, OD Green, Coyote Brown, Gray, RAL 8000, Carbon).