All i've used nosler brass for is 300 wby. I did have to reduce loads from my previous max when I was using Remington brass. i've never used Norma or wby stamped brass in the 300, if I had I could probly make the connection as to if Norma were the manufacturer of nosler.
I would lean toward it being Norma brass tho. If it were lapua, I think there would be a much bigger buzz about it in the shooting community.
Hell, it could be hornady for all i know.