Plenty of food scales and stuff like that are small enough to weigh grams...........you have to realize though that even precise Apothecary scales have a 5% margin of error so you can expect more then that from some cheap spring operated food scale. The % of error shouldn't be of much concern though as the mass you will be weighing is enough that it won't effect you unless it is WAY off.
Homemade grain scale.
