Re: stainless steel pin media
hunter29180 & stev32k:
I would note that perfectly clean interiors of cases is not necessarily an advantage. The carbon residue from firing is a lubricant for the bullet as it is seated.
The neck tension the case has before bullet seating gives the inside diameter of the case an approximate 0.002 inch interference fit to the bullet (by design). Without the carbon residue the bullet might seat hard, collapsing the case wall.
If you just have to use this cleaning method then use an inside the case neck lubricant. NECO offers a graphite you apply by dipping only the neck into a bottle of small metal balls and powdered graphite. There may be other methods too (??).