just out of curiosity what caliber and what weight bullet are we talking about. A 9 x 18 in a 9mm luger box might be a issue if you think you might be able to squeeze a .363 bullet into a case made for a 9x 9. If that is a problem use your mike and see what the diameter is. Otherwise I would think any discrepancies would be pretty obvious and easily checked using your scale. I certainly cannot imagine cases weighing outside a grain or 3 of each other, nor do I know of any bullet that comes in 5 grain increments.
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