OP........I have done lots of inside and outside neck reaming through my wildcatting days. I have found for removing donuts that the best thing is to full length size without expanding ball and inside neck ream with a reamer sized to .001" over the measured inside neck dia. This does not cut your existing neck out of round and removes the excess brass at the donut. I then mandrel expand the neck to the correct size for desired neck tension, load and fire. I have found this to be superior to pushing the donut out and outside turning as the brass memory tends to still leave excess brass inside and a smaller donut still exists when the bullet is seated. Inside reamer sizing is critical though, no more than 1/2 to 1 thou over neck inside dia.



















































