The 300 magnum and the 375 has the same case diameter as they asre based on the ither the 300 or 375 H&H Case. So is most of the Weatherbys cartridges and winchester magnum belted ones like the 264, 300,338,and 458 win mag.

the 375 is a exellent choice and it has more availvable ammo and brass for it then the 400 H&H. Plus there is so many bullets availbele that is designed to be used for various hunting situations.