"Why would a handloader need such a scale?" a fellow asked me privately in reference to my ad about lab balances in Free Classifieds. "Isn't a tenth of a grain close enough for accurate loads?" I answered him there, with the following --
<br>
<br>CONSISTENCY is the key to the best performance, and charges weighed nominally to the nearest 0.1 grain aren't necessarily that consistent. Consider this:
<br>
<br>A charge that the ordinary powder scale says is (for example) 54.6 grains can actually weigh as little as 54.551 grains or as much as 54.649 grains -- a range of 0.098 grain, which rounds-off similarly to a DIFFERENCE of 0.1 grain while still registering as a "consistent" 54.6 grains. IOW, your "consistent" charges may be different from each other by as much as 0.1 (0.098) grain.
<br>
<br>If you're loading something like 135 grains in a .460 Weatherby Magnum, an inconsistency of 0.098 grain is only about 0.07% of your nominal charge weight. If you're loading my old favorite .38 midrange load of 2.5 grains, that same "little" error is 3.92% of the charge weight that you think is always and only 2.5 grains.
<br>
<br>I think it was Phil Sharpe who wrote (in his Complete Guide to Handloading, I think), without any explanation as I recall, something to the effect that to weigh accurately to the nearest 0.1 grain (0.100 grain), the scale had to be accurate to the nearest 0.001 grain. He was right.
<br>
<br>Consider also that you can trust a good scale only when it's new, clean, unworn, and set-up properly (level, steady, etc).
