Originally Posted by Shortmagman
One of the things that the people that first reloaded the Short mags found was that they seemed to move the shoulder of the cases more that most rounds. As a result the shoulder must be moved back a few thousands before they would chamber in the gun that they were fired in. I am sure that with a load that is not full tilt would move the shoulder less and would not need to be moved back, but high pressure loads do move the shoulder.
Because of this I have always full sized my 300 WSM's, 270 WSM, and 7 mm SAUM.
Not to be argumentative because everyone has there preferred method of sizing for there needs.
I don't shoot hot loads any more and if I want more velocity out of a bullet I simply go to a bigger
case and/or longer barrel.
The concept of the 40o +or minus shoulder was for more case capacity and the up side was less
The old case designs like the 300 H&H with a very long 8.5 shoulder angle was notorious for case
stretch (Sometimes up to .030 thousandths after a couple of firings.
I have yet to have to trim any of my short mags. and I only neck size as needed. I rarely move
(Bump) shoulders on any cases.
I do however run little or no head space and like I said, I back off MAX loads.
Full length sizing Every time is very consistent but it is hard on brass and Does effect accuracy to
a small degree. The rules are different when reloading to squeeze every thousandth of accuracy out\of a weapon in my opinion.
J E CUSTOM