Norma makes the brass for Weatherby and Nosler. They simply stamp the brass with the "Weatherby" and "Nosler" headstamps instead of Norma.
Weatherby and Norma brass are identical, other than headstamp.
In my opinion, the Nosler branded Norma brass is the best of all of them, because once it gets shipped to Nosler in bulk, they check for concentricity, weight-sort each case, and chamfer and deburr the cases before they package them. Those extra few processes make it worth the extra money, IMO.
Hornady is not bad brass either. Not my first choice for magnum calibers, but it's better than others (Remington & Federal) in my experiences.