The Grim Reapers break down into 12 different parts. The instructions tell you to check for proper blade tension and if a blade doesn't want to open or opens too easily, you have to disassemble it and tweak the inside parts, reassemble and check again.
When I first shot the Grim Reapers, one of the heads had a blade that was under less tension than the others. Sure enough, the blade came open on release and the arrow path looked like a cork screw. On about the third round, another blade came open on release. I had my BH target strapped to my waterhose reel. The arrow cork screwed down and punched through the hose.
From what I understand, once you work out the kinks, these are some devastating broadheads, but I just decided to go with a fixed blade and not have to worry about potential problems when the shot involves a deer.