I'm not a fan of using the 270 win on elk,but it has worked for many,many hunters.

Now with that being said,I would use a quality bullet and take shots no farther than 250 yds on a good mature elk.Thats farther than most pepole can efectively shoot,past that you run to much chance of hiting the shoulder bone,and that will flat put a stop on a 270 win.
BBJ