ArcticGator
Formerly 'TrevorBD'
Alright so I have recently built a new rifle, it is a 300 Terminator that defensive edge chambered/barreled the action for me. It came with their custom dies which are Redding type S bushing dies. I have been measuring anywhere from .006" to.008" runout of a seated bullet after resizing the case, bumping shoulder back .0015".
I have measured runout of the neck on a fired case (nonsized) and its near perfectly concentric, less than .001". Resized the case, then measured again with a reading of .006" runout. Narrowing down my problem to the sizing.
The sizing die came with a sizing button in it and I had been using it. After researching and coming to the conclusion that sizing buttons are typically not great for very concentric sizing, I went by Redding's recommendations by measuring the neck of a loaded round (.308") and using a bushing .001" smaller in diameter. So I ordered a .307" and a .306". I threw the .307" bushing in, lettering down, (left the shaft for the sizing button in the cap with the little locking ring that acts as a stop for the bushing) tightened the cap and backed it off a hair just like Redding says to. Measured a fired case, less than .001" runout out, then sized it, with the new bushing and no sizing button, and still got a new runout measurement of .006".
I have tried many things-
Removed the snap ring for the shell holder and applied grease to it to allow it to float, floated the die itself with an o-ring, tried different shell holders, tried the other bushing, all with no help at all to my issue.
I am starting to point the finger at my press maybe? It is a RCBS rock chucker. Just wanted to see if anyone with more experience than myself can shed some light.
I have measured runout of the neck on a fired case (nonsized) and its near perfectly concentric, less than .001". Resized the case, then measured again with a reading of .006" runout. Narrowing down my problem to the sizing.
The sizing die came with a sizing button in it and I had been using it. After researching and coming to the conclusion that sizing buttons are typically not great for very concentric sizing, I went by Redding's recommendations by measuring the neck of a loaded round (.308") and using a bushing .001" smaller in diameter. So I ordered a .307" and a .306". I threw the .307" bushing in, lettering down, (left the shaft for the sizing button in the cap with the little locking ring that acts as a stop for the bushing) tightened the cap and backed it off a hair just like Redding says to. Measured a fired case, less than .001" runout out, then sized it, with the new bushing and no sizing button, and still got a new runout measurement of .006".
I have tried many things-
Removed the snap ring for the shell holder and applied grease to it to allow it to float, floated the die itself with an o-ring, tried different shell holders, tried the other bushing, all with no help at all to my issue.
I am starting to point the finger at my press maybe? It is a RCBS rock chucker. Just wanted to see if anyone with more experience than myself can shed some light.
