Tip #1: Stability & Vibration
The scale must be on a rock steady table. A table that wiggles just isn’t going to cut it. If your bench doesn’t have adjustable feet, place shims under the legs. Remember to protect your scale by taking it off the bench before hammering any shims into place.
Even if the table doesn’t wiggle, vibrations through the table can effect measurements. If possible, move the scale to a separate table that is isolated from the press vibrations. If that is not possible, make sure that you aren’t doing anything else while weighing. The press may not be the only source of vibrations. I’ve seen more than one or two reloading benches sharing a room with the clothes washer and dryer.
The wife doing laundry while you are dialing in a powder weight is not a good idea. Just how you go about getting her cooperation on this is a whole other can of worms! Analytical labs place their scales on heavy marble or granite tables. The mass of the stone slab absorbs vibration. But these are too large and expensive for the average reloading bench.
I’ve also seen anti-vibration foam pads that you place under your scale to absorb vibrations. Before you buy one, just try an old mouse pad and see if it helps. I took both concepts, combined them, and designed my own anti-vibration pad. I took a brick, set it on an old mouse pad and placed my scale on top. It works and costs practically nothing.
Tip #2: Leveling
I originally thought this would be the first and most critical step of this list. As it turns out, leveling is not as critical as I would have thought with modern electronic powder scales. Many don’t even have adjustable leveling feet, just three or four fixed feet.
If your bench is level enough that bullets aren’t constantly rolling off the edge, it is probably okay. But if you needed to shim the feet to make the bench stop rocking in Tip #1, you may as well take the time to level it while you are there. If you do want to check that your scale is level, buy a small bubble level that you can place directly on the weighing pan. Make sure it is the right size to rest flat on the pan and that it doesn’t weigh more than your scale’s capacity. I bought a lightweight, plastic bubble level at Home Depot for less than three dollars. Leave the scale turned off while leveling.
Tip #3: Batteries and AC Power
A weak battery can make an electronic powder scale give erroneous readings long before it ever goes dead or gives a low battery warning. I load a fresh battery in my scale every six months or so and use the old battery for some other less critical application. Buy a good quality battery. This is not the place to use a cheap battery.