I load for a friend of mine with a .308 Norma Mag in a custom 1903 Springfield. Other than a half a degree difference in the shoulder they share the exact same data. The Sierra manual list data as well as Barnes and Nosler. I have had better luck necking up 7mm Rem. Mag brass. Necking down .338's was problematic in my friends rifle. Good shooting and good luck! Let us know how you make out.
