For deer, I usually stick with land mines. It eliminates having to calculate wind speed, leading the deer, etc.
For squirrel definitely go with the .50 cal BMG. Y'know how those little suckers always run to the other side of the tree? NO PROBLEM! Just shoot right thru the tree!
However, I am still trying to find a good caliber for Blue Whales.
What we have here is... failure- to communicate.