I've been using the 130g .277" NAB in my .270 WSM and I'm getting 0.5-0.75" groups at just over 3300fps and good on game performance at 300-400yds. Haven't shot anything inside 300 with it yet.
However, the the .284" 140g NAB out of my .280 performed really well on a 180# deer at 50yds. Deer was quartered to me. Bullet entered high just in front of right shoulder and exited low just ahead of the diaphragm on left side. Deer collapsed on the spot.
