ORIGINAL: grndhntr
I have shot 2 elk with a crossbow and 4 with a recurve. I used the same BHs for both. My Zwickeys have never failed me, but any solid fixed blade head will work. Magnus, Zwickey, Grizzly, etc. I have never found a reason to use a BH that costs $10 when a solid $3 BH flies well and will not break when you hit bones. More importantly is overall weight of bolt/ arrow. I use 650 gr. for elk and from my experience I will not use less than about 575 on elk. I know what you're thinking "that's ridiculous, why would I want to shoot such logs out of my crossbow". I have done testing and out to 30 yds, you only loose 4" of trajectory from a 650 gr. bolt compared to a 400 gr. bolt.
Grndhntrm, how far did they run after the shot? I shot my first one at 40 or 50 yards with my 300 and it swapped ends and ran full tilt. The first shot took it's heart out and both lungs. I wasn't going to stop so I had to plug it again at 100 yards. It showed no reaction other than just plain running. I've shot plenty of deer, antelope and a few moose and was quite surprised at their lack of reaction. I thought for a moment that I missed. Tough buggers!