I'm shooting a 300 Whisper out of a 10" barrel and settled on the Remington 125 PSP bullet. The Nosler 125 BT and Hornady 130 gr SSP bullets were slightly more accurate, but at 2000 fps I didn't like the way they worked on gallon milk jugs filled with water, the Remington bullet perfomed better.
I used the Remington bullet to take a spike buck this season, had complete pass through on a just behind the shoulder shot at 30 yds. Ended up with a dead deer that travelled maybe 80 yds after the shot. Not much of a blood trail however.
You may want to try the Remington 150 gr RN bullet, it performed well in my water jug test, but it wasn't as accurate in the Whisper as I wanted.