Used the 140 Amax a few years ago in a 6.5-284 to fill a couple of antelope and deer tags. The shots where all past 500 yards and the Amax worked perfect but I have no idea what they would do inside 300 yards with more velocity????? Me thinks they would act like a Vmax??
If the shot is a little closer than you'd like, really make sure to put it in the boiler room. I shot a buck at 80 yards with a 162 Amax from my 7 RM. He did a back flip and that was it. Completely destroyed the heart and lungs. My FIL shot a buck at 200 with a 168 Amax from his .308. It was quartering to us, but same result - DRT
Just put the bullet where it's supposed to go and it'll do its job fine.
My wife and I have shot several deer and antelope with the 162 Amax from a SAUM. I believe the closest was around 200 yds, with the furthest around 500 yds. The only reason why we aren't still shooting them is because the rifle shoots the 180 hybrids better. If the rifle shot them the same we would have stayed with the Amax because of the cost, if nothing else.