Stocks

A3 stocks fall into two practical categories: direct-fit replacements that swap into the original receiver-end interface, and 1913 Picatinny-mounted stocks that ride a Picatinny adapter for maximum modularity. For a duty-grade build, direct-fit options offer the cleanest aesthetic and the simplest install; for a 1913-equipped host, the modular options open up cross-platform compatibility — the same stock can ride a Stribog or a Bren 2 with an adapter swap.

Every stock in the lineup ships with explicit fitment notes; if a product fits multiple variants via adapter swap, that's listed in the spec table on the PDP. We don't carry stocks we haven't tested — every option here has been confirmed against the platform we list it under.