Re: Weatherby 340 ?
The first rifle I bought myself was a .340Wby. It will do anything that my .338 RUM will do. Im kickin myself for selling it to my Dad (he loves it too). It is close to the RUM in velocity but on a nicer (personall prefrence) action. If your uncles .340 is stainless BEG him to sell it to you. You can build just about anything on that action.
Wy .340 liked almost any 250grainers I ran through it, but I specifically recall the gamekings. I never shot this rifle beyond 400 yards, becuase it was before I got into LR hunting. I dont know about factory loads, but you should be good with most factory loads, i think Wby garantees MOA with their factory loads, although I dislike Barnes bullets. Have fun on your elk hunt!