RE: .308 or 300 ultra mag?
I currently own a 300 RUM and can honestly say i wouldnt recommend it for your situation. I really like mine, however its not a regular use rifle where i hunt. There are alot of better choices for antelope than the 300 Ultra. Like stated before ammo is expensive, and recoil is high. With currently owning a .270, I would suggest a 300 Win mag as a fine compliment.