Thread: Fl sizer not sizing the neck?

Do you have good measuring gear? Measure the diameter of the expander ball, the neck thickness of the brass (times 2 for both sides of the neck) and add together. Compare to the inside measurement of the neck sizing area of the die and also the diameter of the bullet you are wanting to use and this will give you an idea of whats going on. The other one is size one case and mark it with tape and place to one side. Then take the expander ball/decapping pin out of the die and run another case through the die and again mark with tape (I use masking tape and write on them).

Try and push a bullet into both cases, if the bullet won't fit into the case that went through without the expander ball but drops into the standard resized case then you are getting to much expansion of the case neck off the expander ball when you are removing the sized case out of the die. If the pill drops into both cases the same, it would be most likely that you aren't getting enough resizing on the case necks i.e. the neck thickness is insufficient for the specification of that die. If you are finding that the case without the expander ball going through it grips the bullet but the expanded case doesn't - there are two situations that might be at play here one being the expander ball is too big and expanding the case too much, the second being that the brass is springing up too much for the size of the expander ball.