I would say it is the draw length....is this a module system? Also is this a quad limb bow?
lastly, does it have a yoke/harness system (a y shape split of the cable or a V shape short piece and seperate cable at the top) ? I am guessing Y split.

If it is a module system, this low poundage is not that uncommon and if it would happen to have a short yoke/seperate cable, your yoke could be stretched. I have seen this on Hoyts before (rare). I am gonna chalk this up to a moderate priced bow and cam module system that does not allow for retention of the original draw force curve with changes of the cam module (which is very hard to do and takes lots of costly design work reserved for top end bows)

Besides that....63 is plenty for anything besides dangerous game.

You can always take it to a GOOD bow shop that can add twists, or most likely a new shorter string/cable system (or yoke if it has one, but I am doubting it does) and add enough preload (STRESS) to the limbs to get that 70# you are seeking out of it.

Before doing anything that could blow it up (and the above could) you might want to call Bear and see what they say, maybe they will authorize a return and get you some new parts on your bow. Never know till you try!

Sorry this post is actually backwards....sometimes I have to walk myself through the issue to!!

Good Luck Fla. Outlander. Let us know what Bear Says or You Decide to do.