A load engineer from Federal once told me if your powder charge is below 80 grains, try it first with the non-magnum primer and see what happens. I did and it worked, in my 300 Win, H&H, 338 and 375, I get more consistent accuracy with non-magnum primers. Years ago I bought a bunch of primed Fed brass in 338 and it came with 210s.

A good principle to guide me through life: “This is all I have come to expect, standard lackluster performance. Trust nothing, believe no one and realize it will only get worse…”