Thread: Full Length or Neck sizing. What is better and why?

simple terms "shoulder bump" means pushing the shoulder of the fired case back a few thou using FL die, just enough so the sized brass chambers with ease. ie there is little or no resistance when you close the bolt.
You can test you're fired brass before re-sizing simply by chambering them. If the bolt close feels tight or requires some force then you need to bump the shoulder back. If there is no resistance on bolt close then you could simply neck size. If you get tight bolt close you should set you FL die up so that you only just moves the shoulder back slightly (like 2 -3 thou), then check the sized brass again by chambering it. If its still tight on bolt close then adjust your FL die down by 1/4 turn at most, and repeat until you get an easy close. Some of us like to target having slight resistance on close of bolt. Once you set up your die for that rifle it should be set to go for "minimal FL sizing and correct shoulder bump".