I'd tighten the limb bolts down until the limbs just touch the riser, then back them off 1/8th-1/4th turn. Then recheck it. If it's still on the light side, I'd say you need to check your string and cable lengths, ATA, and BH. Get them all to spec, then the bow should hit that 70# mark.
2006 Rytera Bullet X 60#---2008 Moab 70#
2008/12 Firecat 60#--- 2010 Warthog 70#
2010/2012 Alien X 65# 2011 Onzas 60 & 70#
2009 Warthog 70#---2009 Firehawk 70#
2010 Strother SR-71 65# & 2012 Strother Rush 65#
I hunt, therefore I eat. lol