I agree with Mike on simply buying one. I used my BRNO .358 Norma Mag for 3 postion shooting for a while, before re-barreling it to a .375H&H. The recoil was virtually identical, with possibly a slower, softer punch belonging to the .375.
: I much rather shoot a .375 than any of the .300 mags. I've shot several .338 Winchesters that kicked much harder, yet others that felt like poorly stocked .30/06's.
: Stock design is very important.
: If you don't "need" a .375 for DG, then buy the Ruger #1 - you'll be happy. A great big game rifle for North America and much of Africa.