this is the scale that I use I zero it with a dollar bill = 1gram works great!
I just use a balance type scale that is made for weighing powder, accurate to 1/20th of a grain (more so if your eyes can focus on exactly how far between two marks you are). Bought it at Cabelas.It works great and no worry about calibration accuracy . The purely balance mechanical scales have advantages.It costs about $30 if I remember correctly.
I just bought this... I guess I'll see how it does soon.
Did an Amazon.com search for my purchase. Here it is. I'm quite pleased with it for the use I get. It certainly opened my eyes as to how varied any tin or box of ammo actually weighs out.