F5 MFG CZ Bren 2 ACR Modular Stock System

The factory CZ Bren 2 stock is a four-position folding unit that handles the basics well but lacks cheek-riser adjustment for high-mounted optics and offers a polymer-on-polymer fit that develops play over time. The F5 MFG CZ Bren 2 ACR Modular Stock System swaps the factory stock for a Magpul ACR-pattern folding stock through a Bren 2-specific billet aluminum adapter.

The ACR stock geometry adds an adjustable cheek riser, which is critical when running an LPVO or magnified prism on the Bren 2's higher-than-typical optic deck. Length-of-pull is adjustable across a wider range than the factory four-position stock. The folding mechanism mirrors the factory side-fold direction, and the rifle remains operable with the stock folded.

F5 MFG offers three configurations through OpticsPlanet starting at $225.99, with the higher-tier variants adding cheek riser upgrades and ACE-style stock geometry. The base configuration is the most-purchased option. This is a stock-system upgrade for shooters who run the Bren 2 in a precision or duty role and want a more rigid, more adjustable stock than either the factory unit or the SB Tactical brace can provide. Pistol-configured Bren 2 Ms owners should stay with the SB Tactical brace; this stock requires a rifle or SBR configuration to use legally.