RE: 338-RUM 340-Wby or 375-RUM???
Either the 338 or the 340 would be a great choice if you had to shoot longer ranges. They fly pretty flat for a big dia bullet. Their power is not much less than that of the 375rum. All they would be good choices for heavy or dangerous game. Bullet choice are leaning towards the 338. Only using it for close shots I think the 375 would have that extra thump.