Originally Posted by angus-5024
I would use your 300 win and have the .270 WSM as a back up.
Same here. There is a well known poster on this site who regularly gets elk to 1000 yards with his 300 WM. You already own it so use it. If you have to spend money then make sure you have excellent optics and spend range time practicing.
The 270 WSM is a great backup rifle. Remember, the 270 Win has probably taken as many elk as anything else and the WSM has even more power. With a well placed shot you're good to go.
If you really, really need another elk rifle (or you need to tell your wife you do) then go with a 338. However, there is no reason that the two you already own would not do well. Buy a 223 or better yet a 243 and practice as much as you can if you want another rifle.
Oh, and the 6.5x284 would gain you nothing over the 300 WM and 270WSM.