I ran across a place that I can get small digital scales for a cheap price. They weigh in grains with .1 grain accuracy. Price could be in the $20ish range. They want a minimum order of 100. I'm looking to see if I could split the order with a friend who has a store in town.
The one that I looked at was sensitive enough that you could blow on it and get readings.
They also weigh in ounce and grams.
there is a few different models that might work for loading.
If there is any interest, I'll see what a firm price would be and get some pics to post.