Experimenting on some Peterson 6mmBR cases that have 3 firings on in my rifle.
Process: Brass gets FL sized in an LE Wilson die with a .265” bushing. Fire formed brass measures less than .001” run out both inside and outside the necks. FL sized brass is usually under .0025” both inside and outside the necks.
Fed through a K&M expander marked for .002” tension, my run out goes up significantly; anywhere from .003” to .005” inside the necks.
Ive tried both case lube and Redding dry neck lube while expanding. Tried leaving the mandrel loose in the press as well as locking it down. Spinning the case as it meets the chamfer of the mandrel. Expanding, rotating and re-expanding... I’m at a loss.
My last culprit other than the mandrel/holder is the press itself. I’m using an original RCBS JR from the 80’s, with about 18 years service to me. It’s plenty sloppy, but part of me doesn’t want to blame the press if leaving the die loose to induce slop should promote self centering.
Any suggestions on keeping my run-out in check during expanding?
Process: Brass gets FL sized in an LE Wilson die with a .265” bushing. Fire formed brass measures less than .001” run out both inside and outside the necks. FL sized brass is usually under .0025” both inside and outside the necks.
Fed through a K&M expander marked for .002” tension, my run out goes up significantly; anywhere from .003” to .005” inside the necks.
Ive tried both case lube and Redding dry neck lube while expanding. Tried leaving the mandrel loose in the press as well as locking it down. Spinning the case as it meets the chamfer of the mandrel. Expanding, rotating and re-expanding... I’m at a loss.
My last culprit other than the mandrel/holder is the press itself. I’m using an original RCBS JR from the 80’s, with about 18 years service to me. It’s plenty sloppy, but part of me doesn’t want to blame the press if leaving the die loose to induce slop should promote self centering.
Any suggestions on keeping my run-out in check during expanding?