Ok this is an old thread, but whatever. I could not resist the temptation any more and ordered a 224 Grendel barrel fro ar15performace. Can I size 6.5 Grendel down to 224 Grendel brass with a Hornady Custom full length sizing die in one step, or do I need to go a Redding type s bushing die? From what I have read, most are using the Redding die, but I cannot find any reports of anyone trying a one step sizing. For what it is worth, AR15Performance lists the Hornady die set as an add on for the barrel.