It would be better if you started with one in 7mm Rem Mag, that way it's just a simple rechamber job. But if you want to start with a .270, you'll either need to have the bolt opened up with a Sako extractor installed, or a new bolt with a magnum face. You will then need a barrel installed. I don't know what others charge, but all this would run about $700 out the door at my shop. Currently the local Wal-Mart is selling 7mm mag 700 ADL rifles for $325, and I would get about $75 for the rechamber. Lots of ways to go, depending on how you want to get there. Of course the main question to ask is what do you hope to gain by going from a 270 to a 7mm STW? You'll have much more blast, recoil, cost to shoot, etc. You gain lots of energy, shooting 160gr. bullets instead of 120gr. at roughly the same speed. Is it what is needed? Not trying to slam anybody for their choices, but it's important to look at the whole picture as well. BTW, I build a LOT of 7mm STW rifles that folks are really happy with, but wouldn't want such a thing myself because I have no need for one.