I have FL sizing die for the 243 and Lee collet die. Collet die works very well. Partical sizing works very well also. draw back of non collet dies is the expander ball always streachs the case's some, collet dies don't. To partical resize everyone claims to bump the shoulder. I don't buy that. Instead come short on the shoulder a couple times and the case won't chamber again without FL sizing. At that point start screwing the die down about an 8th turn at a time. Size and try that case in the chamber. Keep doing that until the case chamber's freely and the case doesn't rub on the bolt face. You cannot bump the shoulder and make the case work properly without doing some FL sizing. But once you get the die set so that the caswe that would not chamber, chambers easily, you'll be moving the shoulder very slightly and if you move the shoulder at all, the die walls will come into contact with the walls of the case and move it just a hair. That would be a properly set FL die for the rifle's chamber. Only draw back is the FL die still squeezes down the neck and expander ball opens it up just a bit and the case streachs a bit every time.