The 6.5-284 Shehane is basically an improved 6.5-284. Like most Ackley designs, it's easily fire formed and provides increased powder capacity/ velocity over the 6.5-284 Norma. While it has proven to be a successful competition round, I would not go as far to say it's the preferred 6.5-284, with the standard Norma version being the most common in use by a fairly wide margin. Being well proven, using slower powders like Retumbo, and top quality Lapua brass, I personally find the standard Norma does not give up enough to warrant the added requirements/steps of the improved version. IMO.