I've been shooting 100 grain Thunderheads for years, and have had great success with them on animals up to the size of elk and shiras moose. I've shot a number of elk with them, and a moose and most animals have died within 100 yards or so. The last elk tag I drew was a couple years ago, and I had a 41 yard shot at a small 6 point bull. I had a complete pass-through and he layed down in about 75 yards. My moose took two arrows, only because he gave me an opportunity to shoot him a second time. Both arrows were pass-throughs and he died in sight. I've never had a problem with Thunderheads in any manner.

I'm leaving in two weeks for one of the top limited entry archery hunts in Utah, and I'll be shooting Thunderheads again this year.