I am building one of the same.
I am using a 110LA that was a 223.
should be no prob just change the bolt head
I would say build using a .308 barrel (that is what I am doing) as there are a lot more bullets to shoose from.
As for the new 7.62x39 from Savage as I posted in another thread, I called Savage and was told .308.
Good luck.
T