When you size your cases with the Lee collet die do it two or three times turning the case each time and be sure to use plenty of pressure on the handle each time. You can just cut the decapping pin off the Lee collet sizing die and order a new one from Lee.
There is no sizing button on the Lee collet die that is pulled thru a sized down neck to bring the case back to specs. It's all done by the collet pressure of the fingers at the top of the die pushing the case against the mandrel of the decapping pin.
Here's a pix of the die taken apart. Given if your using a Lee Collet die. If not then just ignore this post.
