Quote:
|
When you resize, the sides of the case get squeezed down, pushing the shoulder forward. This elongation remains until the case shoulder meets the shoulder profile in the die, after which it gets extruded back,
|
A reloader can shorten the distance between the shoulder of the case and case head, the reloader can not move the shoulder back; when sizing and forming a case the shoulder the reloader starts with is not the same shoulder he finishes with.
Proof? I am the only reloader that has scribed a case; In my opinion the best place to scribe a cases is at the shoulder/case body juncture. When I fire a case the shoulder on my cases do not move, the nice thing about that is: The shoulder on my ejected case is not the same shoulder I started with.
And then there is the confusing part; If the firing pin drives the case forward the case has no choice but to stretch between the case head and case body.
One more time: I have fired cases in one of my chambers with .127" clearance between the shoulder of the case and shoulder of the chamber. after firing I ejected the cases with my original shoulder .127" behind my new fire formed shoulder. And the neck? The short neck was proof my original shoulder did not move forward because it was very short.
I could ask: Where did my shoulder go? My original shoulder did not move, it became part of the case body and the neck of the case became part of the shoulder.
F. Guffey