Ruger American Rifle Magazine .223/5.56/204 Ruger/.300 BLK 5-Round Black 5RD. 223 Rem 5.56 NATO 204 Ruger and .300 BLK. Magazine fits flush with the stock and offers a smooth feed. This magazine fits stocks equipped with a removable short action magazine well assembly. Genuine Ruger Factory Accessory. Specifications for Ruger American Rifle .223/204 Ruger/.300 BLK 5-Round Magazine: Manufacturer: Ruger Color: Black Magazine Capacity: 5 Round Caliber: 5.56x45mm NATO .300 AAC Blackout .223 Remington .204 Ruger Gun Model: Ruger American Rifle Gun Type: Rifle Quantity: 1 Included Accessories: Standard Condition: New Package Contents: Ruger American Rifle .223/204 Ruger/.300 BLK 5-Round Magazine What firearm models does the manufacturer say Ruger American Rifle .223/204 Ruger/.300 BLK 5-Round Magazine is compatible with? The manufacturer says that Ruger American Rifle .223/204 Ruger/.300 BLK 5-Round Magazine is compatible with Ruger American RifleRuger 90440-5RD: American Rifle Magazine .223/5.56/204 Ruger/.300 BLK 5-Round Black