The action is a long action and the bolt face will work for 7 wsm, 7 rem mag, 7 stw, and 7 rum. Your limiting factor is the mag. if you can get a mag system from those companies than you can go with that. check out this link it has what you can use with your bolt face http://www.longrangehunting.com/foru...iameters-36661
with the tikka mags I think as big and long as you can go is the 338. Hope this helps just wanted you to know all your options. I think you're ordering a menners stock for the tikka. I read somewhere you have to get new bottom metal anyway if you go the manners, not sure if this is true.
So with the right bottom metal I believe you could rechamber to a 338 edge, 338 RUM, 7 RUM theoretically. I dont know if they have those companies you posted make mag boxes that big for the tikka
You can shoot the 7WSM with just a rebarrel. The boltface and mags will work