First: I was thinking 'drawing', but said 'extrusion'. I meant 'drawing'.
Originally Posted by masterofnone
, you beat me to it!
But here's a link
from the same site that describes the priming process.
Thanks for the links. I just found the rimfire priming link on my own, but it's nice to have a direct link.
To ensure that the mix is uniformly distributed into the hollow rim cavity of the case, both downward and centrifugal force is applied during the spinning operation. A rotating spinner quill enters each case, causing the case to spin at high speed. The working end of the quill forces the wet mix toward the cavity and the spinning distributes the primer mix to uniformly fill the cavity.