The 7SAUM would do very well however, I hope 1400 is not the sustainable number of rounds your indicating. All Fclass shooters I know who utilize this cartridge are replacing barrels at 800 rounds +/-. In my experiences, 300WM is a very viable option. I have only managed 1725 yards so far with one I own but that was the longest distance available to me at the time. Its easy to work with, easy to load, component selections are (easier on the wallet) and done right, you can get significantly more rounds out of a barrel than a 7SAUM. Just my $ .02.