Yep you can do it. Not sure cal is going to matter a whole lot. You'll need to replace the bolt head no matter what as you'll need a magnum bolt head if you use a short action. Of course you could build it off a long action in a mag cal and this should work just fine. Might even give you a little extra room in the mag to seat those bullets out a little longer. Is this a newer centerfeed model you are working with? You'll also have to order a barrel since I doubt you'll find a small shank in 300wsm off the shelf. I'm sure others will chime in before long with lots more info. Several guys have gone down this road. I looked at doing the same thing for a while until I came across a 300wsm used in a shop with accutrigger that looked like it had never been shot for $290.