Boyds' AR-15 Rifle Stocks are designed for fixed stock model rifles with the A2 buffer tube. No adapter is required. Adjustable models will not work with this stock. All finished parts have been CNC inlet to Boyds' House Action.NoteVariations may exist from firearm to firearm, minor fitting may be required to get that perfect fit to your firearm. Natural cosmetic imperfections such as minor knots, burls, heartwood, mineral lines or minor cosmetic fill work are normal and are not considered defective.