My impression is the 150 NBT is a bit stouter than the 150 Sierra, but I'd not hesitate to use the Sierra. Can't really see the need for a mono. The 7-08, like the 308, isn't especially tough on projectiles.
I took a decent 6x6 bull with the 150 NBT season before last... bullet traveled 32" of elk at an angle. Quickest kill I've ever seen on a bull.
My first choice would be the 140 Accubond or Partition if you can get either to shoot. Otherwise, I'd not hesitate to stay with the Sierra.
That's the experience I'd listen to personally. He has THE experience that matters IMHO.
Monos weren't ever meant for cartridges like the 7-08 tho they'll clearly work there. The whole reason they were developed was due to the stress on bullets from >3000 fps speeds.
