I have had my grandpas old remington 721 in 270 win sitting in the closet for years and decided to load for it and see what it can do. Well I have found that I cant get it to shoot very well. The barrel isnt in good shape and the crown is jacked up. I want to rebarrel and rechamber in something without having to add a new bolt head size. Im really interested in the 6.5x284norma 6.5-06 or the 280AI I know there is brass made for the 6.5-284 but I have to form the 6.5-06 out of 25-06 brass. What about the 280AI for brass and dies? I like both 6.5 and the 7mm bullet offerings. I was going to use the 270 for everything..coyotes, deer, antelope, big horn sheep and elk I know the other three cartridges will do the same job but a little faster and further out (elk maybe a little closer in) Performance wise what do you guys feel is best?