82, I too own a 338, but carry my old 270 for elk. I use 150gr Partitions, and I and a 5 X 6 bull know it will kill elk at 450 yards. And a cow at 430 yds. And others at lesser distance.
I would encourage you to seek out a "premium" bullet, IMHO it really ups the performance of a 270. If all I had was cup and core bullets, maybe I'd carry my 338 for elk. Maybe.
Why did I buy the 338? Barely used, it had a VX-III scope and it was too cheap. And I was dreaming of Alaska and big bears. I've never felt undergunned with a 270.
Regarding elk hunting I think "failures" of rifle bullets 25 caliber or larger are usually failure of the shooter, not the instrument.
