Most of the profesionals if we can call them that, will average the weight of a volume measure on a reloading scale then weigh the loads to that amount, this is supposed to reduce the variation in fps .
In actuality I dont believe it has a lot of effect, I am a reloader and have the equipment and tried weighing loads and did not get any tighter groups by doing it. I just hold my measure over a can I keep for the purpose and pour till it runs off on all sides, this was the method that showed theminimum differance when I was testing volume thrown loads[ 25 sample ] the tapping worked the worst for me, and the cut off type measure did not work quite as well as the overflow method. This I am sure will not be the same for every one as we each handle things different. Lee