The new standard cartridge of the SK family. The SK Flatnose(TM) Basic is a new development in our standard line of rimfire rifle rounds. It has a flattened projectile with improved ballistic properties and benefits from years of experience with developing and producing small caliber ammunition. This turns the SK Flatnose(TM) Basic into the right companion for shooting training and competition. Stability and reliability. The new SK Flatnose(TM) Basic.