I decided to scrap my 270wsm project and start on a good long range rifle. I was considering a 280, any ideas? The 284 Winchester also interest me. I would like to stay in the .284 bullet size. What is it that makes a good long range calibur? I know the 7mag is popular but I was under the impression it is not that fast. I always thought fast was flat and flat was accurate. But the more I learn the more I learn I don't know. Any thoughts would be appreciated.
What makes a good long range rifle? In my opinion, it is a rifle that can maintain good velocity, accuracy, and consistency with every shot.
You want a rifle that will be able to offer good ballistics down range. 6mm/.243, 6.5mm/.264, 7mm/.285, .308, and 338 are all viable options due to the large majority of high ballistic coefficient bullets. These calibers offer superior control in the wind, retention of velocity and energy at impact at extended range.
The calibers you are looking at will definitely be good long range calibers, but... but what are they being used for. The 7mm Rem Mag will out perform the 280, and the 284. The 284 loaded properly will mirror that of the 280.
Of the three, the 7mm Mag would be my choice for hunting, but I also like the ballistics of the 284 Win and the 7mmSAUM. All three can be loaded with a 180grn bullet and pushed to 3000+fps. The 280 AI is not quite that fast but also capable of pushing the bullet to speeds of 2900 to 2950fps. The 280/280AI's recoil will be less and use less powder. Some are finding with the 284 Win. that they can use RL17 with a slight improved shoulder they can produce velocities of 3050fps with 180grn Bergers. This is at its max velocity and should be worked up to slowly. There is a very good article on 6mmbr.com (7mm Cartridge Guide
Then you can look at cartridges like the 7mm WSM and SAUM. These two cartridges offer superior ballistics equaling and exceeding in some areas of the 7mm Rem Mag. So I hoped this helped and did not confuse you to much.