Ruger Stock I.D.

I have a Ruger grey/green laminated stock I am trying to I.D. It is for the 77 MKII bolt action type action and is to long for the 22lr and to short for short action centerfire. I think I have it narrowed down to a 22 mag or 22 hornet. Does anyone know the dimensions for the magazine inletting for one of these or are they the same. Thanks.