I have a customized Ciener kit with a dedicated ( 1:16 twist) M4 style flattop. The barrel is an actual Ruger 10-22 bbl made by Model "1". The bolt mod was done by Charlie Tilman in Van Alstine TX. I sell these at gun shows when I can get them. Let me know when or if you would like to aquire one. Rob robgump@gmail.com