I recently purchased once fired winchester brass and a set of Lee RCB dies to reload. First case in press brass broke at the shoulder and the next 4 have severe stress rings around the neck - followed set up from Speer manual on setting the dies and is the same from the directions for set up that come with the dies. Clues what I may be doing wrong? Bad dies? I have reloaded hundreds of rounds for 243, 270, 7mm rem Mag and 300 win mag and never seen these issues before. Help!