I had a .270wby mag made by Cooper. Good rifle, shot great. After several years some old gray beard at the range pointed out to me that my 270wby mag only gave me about 5% improved performance while using a whole lot more powder, with a whole lot more recoil, very expensive and hard to find belted magnum brass, and shortened brass life. I eventually sent the rifle back to Cooper and had it turned into .270win. GRRRREAT shooting rifle. They can give me a faster twist now to use the mono bullets, but I'm kinda happy with my .270 just the way it is. I've killed deer out to 600yds with no problems, Bang flop.