Ruger American Rifle 20 MOA Ruger American Short Action Picatinny Matte Bl. The rail is engineered specifically to fit the American Rifle factory scope mount holes on the gun's receiver. MIL-STD Picatinny slot-and-rail spacing accepts Picatinny or Weaver scope rings. One-piece design is precision-machined from billet aluminum. Base is 6" long with a hardcoat anodized finish and includes (4) TORX mounting screws and a T-10 wrench. Genuine Ruger Factory Accessory. Specifications for Ruger 90678 American Rifle 20 MOA Ruger American Short Action Picatinny Matte Bl: Manufacturer: Ruger Finish: Matte Black Fabric/Material: Aluminum Gun Type: Rifle Attachment Type: Screw Package Contents: Ruger 90678 American Rifle 20 MOA Ruger American Short Action Picatinny Matte Bl Ruger 90678 American Rifle 20 MOA Ruger American Short Action Picatinny Matte Bl