I have full-length sized 50 cases of 300 Winchester Magnum brass. The brass were all once-fired but in two different rifles (some of them may have had different powder charge too). After resizing, I am noticing that the case length (to shoulder datum, measured using Redding Dial-Indicator tool) is not the same for the resized brass. Some are sized to "standard chamber - 0.005 inch". Some other are sized to approximately "standard chamber - 0.002 inch". I wonder what causes this variation:
a) normal tolerance of the reloading press
b) that the brass were fired in two different rifles (but the sizing operation should have eliminated any original difference in length (?))
c) any other factor such as me pressing the handle not with the same force all the time, lubrication issue, etc.
?
I appreciate your feedback and experiences.
Thank you,
-Omid
Last edited by Omid; 07/14/18.
