Could you please rephrase your questions, they are hard to understand.

Yes many people on this site have rifles that they have several barrels for, most call them switch barrel guns. This is very common for Savage rifles because of the easy of changing barrels. Why people switch barrels is a s different as the people that do it, but yes many have several factory "take off barrels" that they use.

You may be surprised your 270 barrel may sell in the classified section. I am assuming that it is a sporter contour, they don't bring much money, maybe $50-$75 bucks, depending on condition, and round count. A lathe is a hard thing to acquire for most people, and is an expensive tool, also reamers are not a cheap throw away tool, but the question is what are you needed a lathe and a reamer for? If your are looking to re-chamber your barrel you have to pick a caliber that uses as 277 size bullet. The 270 is about the biggest thing I can think of that uses a 277 bullet. You could develop a wild cat round with a custom reamer, but remember there would be no load data for it. (I highly recamend that this is for only well experienced loaders, not something for the inexperience.) You may be pushing the envelope of the bullet buy trying to push it harder than a 270 can.