I have access to some high grade scientific scales at the University where I work. They go out several decimal places as I recall,
way further than would be useful in reloading. I'm thinking that I can make my own check weights using a couple short lengths from a paper clip for the smaller weights, and coins for the heavier weights. While weight may vary from coin to coin of the same type, using the same coin of a known weight should not be a problem. I'll just keep them all together in a set.
As for atomic decay, well, I'll just have to take my chances.
