Since my personal experience with newer Tikka rifles has not been as good as many other owners are saying, I personally would not buy another one.
That, plus the plastic, turns me off these rifles.
The 700 Mountain is a very nice rifle, however.
The Ruger is a good solid rifle, and would be a good choice.
In the end, he should handle the possible choices, and see which feels best to him.
Eagleye.