Mike(hensley),
Indeed, you can make cases from 30-40( 303 Brit.also),but it wouldn't be easy. It would involve sizing the case heads,as well as making the dies to do it with.After doing this, turning the rim, trimming,etc.,you can have precisely fitting cases.A much easier way would be to start with original length( 1.125" vs 1.020" current length)38-55 cases. I would think starting with 32-40 Win file/trim die,maybe 25-35,then 6.5x58 die.I like to form cases with out the expander(in case a case sticks), but in this case, you might find it helpful to make a straight rod instead (slightly under bullet dia.).This would be an effort to avoid "crumpling" necks during the pretty radical sizing.The 38-55 cases will start off both shorter and smaller in dia.than 6.5x58R.The radical reforming will lengthen them (maybe enough)and fireforming will expand them to fit the chamber.
Mike
