I've had great luck in the accuracy department with them out of my 280 and 7mag. Both shoot well under an inch if I can do my part. RL22 is the powder of choice in both as well.
So far between my wife and I we've killed 6 critters with my 280 and Accubonds. Including an elk, warthog, impala, bushbuck and wildebeest with the 160's. The smaller game probably isn't much of a performace guide, but I broke the shoulder on the warthog, and impala on the entrance and they still exited after 20-24+/-" of penitration! The bushbuck was a rib shot, and penitration was only 8-10", no recovery... they just arn't that big...
The shot on the elk was a spine shot and I didn't recover that bullet either.
My wife shot the wildebeest bull with the same rifle/bullet combination a couple weeks ago. We did recover that bullet, but in all respects, it penitrated on a quartering away shot from the last rib up through the chest cavity to the oposite shoulder and was found bulging under the hide. Aproximate penitration was probably close to 30"+/-. The recovered bullet weighs about 120 grains.
I shot a big bodied mule deer (300ish pounder) last year with the 140gr accubonds out of the 280 as well. The MV is probably close to 3000fps+/-. Distance to the deer was about 80 yards. The performace was not what I expected, but it did perform better than a standard cup and core probalby would have. The bullet didn't exit on the broadside shot, but the recovered bullet was found just under the hide. The weight was 100 grains even. I think what happened was upon exiting the chest cavity and being pretty flattened out, it dead centered a rib, and blew a big hole through the rib cage. It was then stopped by the hide. The deer went about 3 steps and was dead, squirting blood like a fire hose. The wound channel to all critters was outstanding!
I'm going to put an order in for some 260gr Accu's for my 375H&H and try them out on elk this year. I have a feeling that I won't be recovering anything but a dead elk...