Re: Best choice for long action build..280 ack??
.280 AI is an excellent choice. It can not be beaten ballistically by a .473 bolt-face round. To top it off, its an easy cartridge to load for, has great brass life, feeds well, and has a wide variety of bullet choices. I have a hunting rifle in .280 AI and absolutely love it.
Now that Nosler has standardized it, there is a spec for it and great brass available.
Remember, 7mm Magnum will require a magnum bolt face and will only have the edge on 175/180 gr bullets pushed hard.