First, for setting dies for resizing, I run the ram with shell holder all the way up,set a dime on top of the shell holder,and screw the die down until it hist against the dime. Tighten the die and resize. This sizes enough of the case to allow easy chambering.Crude but it works.
Second, keep practice rounds a bit more moderate. I think this helps reduce stretching of the case.
For BG hunting, use new brass...no need to use fired brass for BG hunting and for the type game to which the 375 is suited,reliable chambering and function is paramount and new brass is best in that regard.It is't necessary to have brass formed to the chamber in order to shoot well in a good 375. If the rifle is that fussy, sell it.
Run all hunting ammo through the rifle to be sure of perfect feeding and function.Then you should be good to go...I am assuming you have double checked your ammo through live fire, that there is no bullet setback for rounds stacked in the magazine.
