Many elk have fallen to the .270. The best ballistic coefficient dictates a 140 grain bullet for caliber. Of Course the Barnes bullets are an exception. Find the bullet you want to use and try as many powders as you can. You will find a powder that pushes that bullet well. Mulies and Elk are both bigger animals than a whiteail, so I would suggest a heavier bullet also. 150 grain at least. Premium bullet advised. That said many have fallen to Remington PSP's off the shelf. If I was spending money on a hunt I would spend the extra cha ching for a premium though. Cheap insurance.