I think the data tables are reversed for FFFg vs FFg at this web site:

http://www.hpmuzzleloading.com/LoadsBallistics2.html

All my APP type powder FFFg wieghs Heavier than FFg.

I also tap my powder measure till it won't hold any more. My findings are:

Trip7 FFg
.80 x grains by volume = Trip7 FFg Actual Wieght

.80 x 80gbv = 64gaw
.80 x 100gbv = 80gaw
.80 x 120gbv = 96gaw



APP/Gold/Pinnacle FFFg
.92 x GBV = FFFg Actual Wieght

.92 x 80gbv = 73.6gaw
.92 x 100gbv = 92gaw
.92 x 120gbv = 110.4gaw