the outfitter won't let his hunters use anything smaller than a 7mag. Said he got tired of chasing wounded animals all over the mountains or losing them.
That's just an ignorant outfitter. If the bullet don't go where is't suppose to go then a 416 Rigby ain't gonna help. The .270 is perfectly capeable of taking any elk that walks this earth. I have been using one for a while now and not once have I needed a follow up shot. Out to about 300 yards or so it will kill elk all day long.
Great loads for elk are........ Federal Premium 140 grain TBBC in regular or high energy or Federals 150 grain Nosler partition.........Winchester 140 grain failsafe and the 150 grain partition gold..........PMC's 150 grain Barnes XLCBT