This one is not as cheap as the 223 reamer, but if you want to make a 312 bullet for your 303 or your 762x39, it is not a bad deal. I am going to make a 312 point form die and use my core swage and core seat from my 308 set.
http://www.ebay.com/itm/330875820588...%3AMEBIDX%3AIT
Rolltide