One thing I do not like about the weatherby brass for the 378 family is the bottom of the powder chamber is below the top of the belt so when you get up in pressure the top of the belt curls outward. A problem as dies do not size it back in. A case on 416 rigby brass is superior. I know Norma makes weatherby brass but weatherby specs it harder in the head. So for me if you are shooting a big weatherby use the weatherby brass.