I own a 7mm-08 84M Montana, and shoot/reload for a friends 280Ai mountain ascent. with the 24" barrel on the 280 I find it balances a little better (a couple more ounces on the muzzle). I have hunted with the 7mm-08 Montana for quite a few years now and the performance on sheep, mule deer and a lone bull elk has all been excellent. The 7mm-08 is roughly 2.5" shorter, so a little handier in the tight stuff, and is a little lighter. I don't think either would disappoint. One thing I will say is the 7mm-08 in my Montana does its best with 140gr flat base bullets - longer heavier boattails just don't fly as well or as fast as I'd like. comparison is 162 ELDX in my 7mm-08 will only run about 2550 to 2625fps with a variety of powders, while the 280AI was easy to get to 2925fps. 300fps is a fair spread.