I recently bought several lots at an auction containing many Dillon accessories.  The problem is several are not marked with a part number or any other marking.  Mainly, they are powder bars and powder dies.  I was wondering if anyone knew of a way to measure and determine whether they are small, large, or magnum powder bars, etc.  Obviously, the small powder bar is easily distinguishable from the large, being that the small bar is actually 2 separate pieces. 

Any help would be greatly appreciated.

Mark