You could collect up a couple 20" take off 243 barrels and send them and a rifle all out to be punched into 243ai with the same reamer/headspace... not saying you should, just saying that is something a feller who likes to tinker and let the idea creep in his head COULD be inclined to do.Thank you all for the feedback. Since I RELOAD it seems just sticking with the 243 is the way to go. i havent seen anything indicating that the extra effort/cost is worth it on the 6cm
