I loaded some 165 Grand Slams into my girlfriend's .308 this year. They shot fine. Took two antelope and shot and lost one deer.
First antelope was facing at about 75 yards. Bullet blew up the heart and exited between the hams.
Here's the heart:
Next one was quartering towards at about the same distance. And dropped it on the spot
Next was a deer, quartering and severe uphill angle at 100 yards or so. I think she hit him in the ass, dropping the deer and rolling him down the hill. Got up and she hit him in the high shoulder (I think), he went down for about 5 minutes, but escaped when we went into the scrub oak to look for him. No blood trail. Found him 200 yards away gimping down the mountain onto private land. No shot. Got permission to pursue, found him again and he ran off pretty well. Never saw again.
Don't know what to make of that performance other than poor shot placement. However, I was kind of surprised by the explosiveness of this bullet. So it's possible it didn't penetrate quite well enough with the butt shot she put on the buck. Or the angle wouldn't have put it thorugh the vitals anyway. Don't really know.