Just as to my own data, I recently shot several 7mm Wby rounds out of my Wby Ultralight Weight through my ProChrono, and I fell in love again with CorBon:
CB is the only ammo I have found that consistently shoots above the specs. The Nosler Ammo in 7mm Wby, .340 Wby, and .375 Wby is however very consistent and accurate.