BX-1 10-round .22 LR caliber magazine is made of black plastic with steel feed and works with any factory original 10/22® Rifle SR-22® Rifle 22 Charger™ Pistol and .22 LR Ruger American Rimfire® Rifle. Magazine will function in the .22 LR Ruger 77/22® Rifle but the contoured base does not match the profile on the bottom of this rifle; the JX-1 Rotary Magazine (#90057) is recommended for this rifle.