I load .30 x .378 and .338 x .378. Full length resize both. The sizer die is set by screwing it down until it stops on a fired case that has the neck cut off in the middle of the neck radius (depending on where you cut the neck, you may want to pull the expander plug). Turn the die in handy on the case, and lock it down. This only works if you shoot the brass in the same rifle. The shoulder won't wrinkle or cave in this way. The .30 by shoulder is a little more fragile than the .338, but both require thin sizing lube inside and outside and thorough cleanup. You may booger up a few cases before you get it like you want it.
Ditto on the primer pockets; mine get loose at 4-5 firings. If I knew how to tighten them up again, the rest of the hull would probably make 4 or 5 more firings.
My go-to hunting rifle is my .30 by, Henry Wayne, (you might be a redneck if you name your rifles). #2 is my 7mm-08 named Ugly Baby. Henry Wayne is sub 1/2 moa, and Ugly Baby is sub 1/4 moa. Both are way better than I am.
Got long winded again, good hunting, Tom
Texas State Rifle Association Life Member
NRA Endowment Life Member
A big fast bullet will beat a little fast bullet every time