The BX-25 genuine Ruger factory magazine has been tested and proven to feed as reliably as the standard BX-1 10-round Ruger rotary magazine. The BX-25 features a stainless steel constant-force spring that provides feed consistency round after round. BX-25 magazines will work with any factory original Ruger 10/22 rifle, SR-22 rifle, and 22 Charger.