A Tikka prefit will thread (and headspace correctly) onto both Sako 85 & A7 actions. While I wouldn't recommend going out and purchasing either action for the purpose of building a semi-custom rifle off of it due to the limited aftermarket stock choices available, if you already have one of these rifles like I did and want to screw on a new tube you certainly can.
The attached photo is of a Sako A7 sporting a Carbonsix Tikka prefit chambered in 300wsm that I'm currently in the process of finishing up.