As of 2005, all Mini-14 type rifles are now based on the Ranch Rifle design, with integral scope bases, a non-folding ghost ring aperture rear sight and a winged front sight similar to that used on the Ruger Police Carbine.[1] These upgraded rifles have serial numbers beginning with 580 and are sometimes referred to as 580 series Ranch Rifles.[10] They also have a new modified gas system designed to reduce barrel vibration[9] and are capable of shooting 2 inch groups at 100 yards (2 minute of angle (MOA) accuracy).[10]