It's my understanding that when Nosler tested the 150AB vs the NBT, the AB produced no performance advantage over the NBT. The 150gr NBT is tougher than you might think.
I'm not so sure about the toughness of the 150 grain Ballistic Tips. I shot an antelope at a little over 300 yards with my 270 Win. The shot was broadside, hit him behind the shoulder, the bullet nicked a rib going in and destroyed the lungs but didn't touch the far side of the body cavity. That's not very tough in my opinion. I would have thought it would have penetrated completely in that scenario.
