Yeah, I have to agree with Jeff, I was wondering that myself. I shoot a 72# razortec at 29" draw with a 420 grain arrow at 279-280fps. This means I'm producing just under 73# of KE. I shot a hog (the one in my avatar) at 20 yards with a cut on contact mech head and it blew a huge hole out the back. I know a guy that shoot 61 foot pounds of KE and has never had any problems with his mech heads. Good Luck.