I still have a Custom rifle chambered in the .338 Imperial Magnum cartridge, I would like some "Help" on forming some new brass for this round. I've read that some can be made from the Ultra-mag's (.300 or .375) if so can the steps be outlined for me.?? I have a set of FL RCBS dies for it, but realize that the head dia. is smaller for the Imperial than that of the Rem. Mag's. Would I need a special die for the base to be sized?? or what steps is there to making this work. Is it pratical?? The rifle is a Sako AV clip feed, with a 27" Smith gaintwist barrel. The Imperial brass I bought back in the 8o's was soft and could not get the full potential out of this round ..!! Thank's for any info passed this way..