Originally Posted by Joaquin B
Unless I am terribly mistaken, the original .275 H & H was nothing more than the 7mm Mauser.
If you are referring to necking-down the .375 Mag's neck to 7mm, the 7mm STW is the same thing, with the shoulder blown out to maximize powder capacity.
I think your thinking of the 275 rigby, same cartridge as 7x57 mauser. I've read the English were trying to disassociate from the HUNS w/the great war kinda not leaving a favorable feeling towards germans.
Or a 8mm necked down & more commonly used, I believe.
Back to O.P. curious why 275 H&H mag? Just something different or is there a gain in throat life or other?