At 80 LBs, caution is needed not to use an arrow that is too light, even with the suggested mininum 5gr per, a 5gr arrow out of a 80 lb bow is would be like mini dry fires and would be loud and hard on bow...
With Easton a .300 gr arrow is needed with the 80 lb, the .300 FMJ although at 12gr per would stil be blazing fast, penertration would be unreal with pass thru and beyond, and your bow would be very quite with much less stress.
The A/C/CŪ Pro Hunting arrow also in a .300 and only 10.4 gr per would be flat and blazin ..
The Nemesis also comes in a .300gr at only 10.7 gr per..
Those would be my three suggestions with easton..
Neil