I have used a .270 since I started hunting elk and it works every time. Granted I have not been face to face with a 400" 1000 pound elk but would feel comfortable taking that elk inside of 300 yards. With todays bullets I feel just a comfortable elk hunting with a .270 as I would have with the bullets available 30 years ago for the 300 or 338. But, Like EKM said If you are going to be hunting elk and larger at least every other year then you might want to step up your rifle. Believe it or not the 400 yard shot on an elk is pretty rare with Arizona and New Mexico maybe being the exceptions.

In other words, you .270 is up to the task so don' t be afraid to use it.