Bob,
The advantage is supposed to be similar performance as a Partition but with a higher BC (though there is not really much difference in most calibers/weights) and greater accuracy for most folks. Accubonds have proven very accurate in all of my guns, and the only bullet I have ever recovered came from a similar shot as yours, but this was a Mid-MO 8 point whitetail (not in the same league as a monster muley) and the bullet weighed 98 grains and was a perfect mushroom. This was also a 140 gr Accubond in 7mm, and was shot from a stout loaded 7-08 with a 24" barrel at about 40 yds. Impact velocity was almost identical to your situation. I'm sold on 'em, at least for the kind of hunting I do where the shot may be as close as 15-20 yds or as far away as 300. Each to his own, just sharing my experience. IMO they are GREAT deer bullets. Haven't used them on anything larger, but I bet put in the right spot, they'd work darn good.