sithlord6512
Beginner
- Nov 24, 2008
- 107
- 0
I want to adjust my RCBS FL sizer die to the correct headspace (have RCBS's precision MIC). I was informed that my brass should be fired at LEAST TWICE before trying to set my die to the headspace of my chamber (RCBS Tech).
I am missing something. Why would firing at least TWICE make a difference - wouldn't I just be resizing rezise my brass back to headspace dimension of the my die each time (i.e., no closer to the headspace of my gun).
Based on some I the things I have read on this forum, the only theory I can think of is that brass will tend to "springback" less with each firing. Therefore, as I fire the same brass in the same rifle a number of times, the less it will springback, and therefore, the more closer a match it will be to the chamber of my gun. Is this theory correct?
If my theory is correct than I figure I can just FL resize as normal. If incorrect, then do I need to consider a different type of resizing (e.g., Partial FL resizing or neck sizing) at first, in order to get brass to the same size as the chamber of my gun?
I am missing something. Why would firing at least TWICE make a difference - wouldn't I just be resizing rezise my brass back to headspace dimension of the my die each time (i.e., no closer to the headspace of my gun).
Based on some I the things I have read on this forum, the only theory I can think of is that brass will tend to "springback" less with each firing. Therefore, as I fire the same brass in the same rifle a number of times, the less it will springback, and therefore, the more closer a match it will be to the chamber of my gun. Is this theory correct?
If my theory is correct than I figure I can just FL resize as normal. If incorrect, then do I need to consider a different type of resizing (e.g., Partial FL resizing or neck sizing) at first, in order to get brass to the same size as the chamber of my gun?