i was picking between 80 and 100 gr glue ons for my 3d arrows. the 80's provided a 8.5% foc. (i ordered some of each). he said that's fine for 3d, but you'd need more for field archery, and i'd imagine more for broadheads. i think i'm around 12% on my broadheads and some guys on here report fine results with 14%- even 16%. hopefully some folks who know, and didn't just ask someone - like me - will respond to what's good for each use mentioned above. i'm just offering 2nd hand knowledge really.