My favorite whitetail deer bullet for my 30-06 is a 180 grain Nosler Ballistic Tip with boattail. It gives excellent accuracy and has a high ballistic coefficient to give great downrange performance. The ballistic tip is somewhat frangible so it leaves a big hole that anchors a deer quickly. For a big muley I would go with a bullet that has more controlled expansion like the 180 grain Nosler Partition or even a Swift Partition as I have use both of those with outstanding results.