RE: RCBS X-Dies
BC - I have only used them on my various Ackley Improved rifles; and those simply don't grow. In fact, they shrink on the first firing - and then just stay there after that. I would like to add, however, that I have had to do a little tweaking on the de-prime rod that goes through the neck on the Lee Collet dies a couple of times. If bullet tension in not sufficient after resizing the neck, shave a couple of thousands off the rod (in a lathe of course) where the collet squeezes againstthe neck. Roskoe