If your scale will measure down to grams or 10th's of an ounce you should be able to see any change if at all within 2 weeks.Good advice from these fellas.You should easily get a 50# hunting weight bow from your stave.
A rule in the future working with woods you've never worked with before is to start wide enough and long enough.A chart to show what your moisture in your bow should be at certain temperature and humidity level.Hickory performs very good at 7% to 9%.Above 11% not as well.It's great bow wood.
As said earlier heat treating the belly of hickory does help with slowing down moisture absorbtion.Be fair warned though it'll gain some draw weight.That and sealing it with a good finish and keeping it inside while not using it will keep it that way.