I'm working with a new 7PRC with a Bartlein carbon wrapped bbl and new Peterson brass. The brass was loaded with various bullets and loads, then fired. I set my Redding Type S FL die to give about .002" shoulder set back. I'm using Imperial Wax and avoided getting it on the shoulders.
The first thing I noticed was that some brass needed more force than others to fully resize. At first, I thought that the wax was applied inconsistently but then thought that the different loads caused the brass to expand differently. None of the loads were hot. I ran each piece of brass into the die twice and gave a second of dwell time at the top of each stroke.
Everything looked good until I measured the base to datum line using the Hornady tool. I found that there was a variation of .003" between the shortest and longest cases. What caused this and what is the best way to avoid it?
The first thing I noticed was that some brass needed more force than others to fully resize. At first, I thought that the wax was applied inconsistently but then thought that the different loads caused the brass to expand differently. None of the loads were hot. I ran each piece of brass into the die twice and gave a second of dwell time at the top of each stroke.
Everything looked good until I measured the base to datum line using the Hornady tool. I found that there was a variation of .003" between the shortest and longest cases. What caused this and what is the best way to avoid it?