I'm being given a Pre 64 Winchester Model 70 on the one condition that I have to made into a .280 AI. Now I'm completely stupid when it comes to doing stuff like this, so I need some help help. And I don't know what caliber the rifle is right now. So what all am I going to have to do to make it a .280 AI? I'm sure i'll have to get a new barrel and rechamber. But what else will have to be done and what do you think a job like this will cost? And whats a good barrel to put on there?