Originally Posted by Winchester 69
I think he's saying that the Lee collet die did the damage. Any chance that it's a 280 die?
Shouldn't matter, all the Lee collets are ~.532 inside.
I think the belt is slightly oversized or the die is slightly undersized and causing the problem or maybe the bottom of the collet has some crap/burrs on it. Turn a case around backward and see if the head will slide easily into the collet. If not clean the die well, then maybe hone the bottom inside of the collet a little to clean it up and make it smooth.