I just recently got a neck sizer for my 243ai. I have a load worked up that shoots .4-.5 consistant on fl sized brass how much better or i should say will there be a big change if i just neck size? Meaning i have some brass that is fl sized and not loaded but dont have piles of brass to just set those aside and not use but i also have some fired stuff that needs to be sized . Is it going to change my load considerable? By the way when i full length size its absolute minimum shoulder set back just enough to close the bolt.