Marble,
I used the 140gr accubond at 3150fps this year and performance was somewhat puzzling, but still good. At 500 yards my first shot was about 10-12" behind the shoulder. No sign of a hit, and upon inspection, no exit. Second shot I held a bit forward and hit him on the shoulder maybe 1/3 of the way up. That dropped him like a stone and the bullet did a hell of a job breaking the on-side leg and plowing through the heart coming to rest in a lump on the far side. I cut skin and the bullet fell into my hand. I didn't weigh it yet, but I'd guess about 50% retention. That bullet seemed to perform excellent, not sure on the other one as we were in a hell of a spot and boned him out without gutting so I didn't go digging for it. On elk with that first shot, I'd prefer to shoot a caliber that will penetrate all the way and if I use the 7MM WSM again I may switch to the LRX or the 160 AB.