Great advise on the 500 yards shots being difficult to consistently make. But let's not beat the horse to death.

I will try to give you some advise to (hopefully) make your hunt successful and memorable.

Just be realistic. See what you can do with your rifle consistently as far as range capability and plan on geting within that range before making your shot.

Bottom line is if you can't do 40 or 500 yards, you'll just have to get closer.