This is my experience with the 139 IB as well. I took a partial box of 140 AB's in a deal and they seemed interchangeable on paper. I've only hunted with the IB and performance on game was impressive, thru n thru (TNT), DRT, and minimal meat damage. I imagine the IB is the same.We've had really good luck with Accubond LR's. My son has shot deer from 30 yards out to 565 yards with a 280 Ack. And all of them were DRT. The exit hole on the 168 grain is a little bigger than a half-dollar. It surprised me that it had the same size hole weather close or far away.