The BX-15® Magnum is compatible with the Ruger Precision® Rimfire chambered in .17 HMR and .22 WMR, Ruger 77/17®, Ruger 77/22® and Ruger American® Rimfire rifles chambered in .17 HMR and .22 WMR. The stainless steel feed lips and "constant force" spring combine with a high-lubricity, polyacetal, anti-tilt follower and durable, glass-filled nylon magazine body to make the BX-15® magazine rugged, reliable and easy to clean.