I started using them on elk two years ago in a 300 Win Mag and have killed two elk. I did not recover the bullets. One at 322 yards and the other at 250. The first was hit in the heart and went 2 feet rolled over and kicked a few times. The other was hit through both lungs and wobbled around and fell after 50 yards. They also have a tendency to shoot into the same hole at 100 yards from the bench. I like them.
http://www.youtube.com/watch?v=kwFP6TeezZc
http://www.youtube.com/watch?v=QGLPCAYfewc