Winchester Lee Navy|Winchester Shooting and Hunting|Forum|Winchester Collector

I recently bought some 220 Swift ammo for the cases.  Has anyone formed these into the 6 mm Lee Navy cases.  Sometimes it is called a .236″ which is the land dimension.  The bullet diameter is actually a .243″. These cases will require some machining but my shooting partner is a machinist.  Looking at the 2 cartridges I really can’t see a way to fire form the cases without some reloading dies?