I can remember that many, many heavy bore dangerous game rifles were made on both the 1917 & 1914 actions................ Which actions good gunsmiths would re-barrel to long cartridges like the .375H&H & into .458's as the action could stand any reasonable loading...........
Yup 1903's were the basis for many fine sporters in a wide variety of calibres, MichaelP has posted some flat out beauties , but I never heard of one being in .375H&H or .458Win..........
be safe, enjoy life, journey well
da gimp
OFC, Mo. Chapter