Home Forums Hunting & Shooting Ask The Gunwriters weighing powder accurately

Just posted the following on the Campfire -- didn't mention there that I'll have the Ainsworth and one Mettler balance there, in case you'd like to look 'em over "up-close and personal."
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<br>If you're close enough to come to Hamilton, Montana (S of Missoula) this weekend (6-8 December), come to my table at the gun show in the Seniors' Center on Adirondac, west of US 93, for a chat. There'll also be enough good-lookin' goodies at the show to make your visit worth your time.
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Dr. Howell, I am a firm believer in precision and reproducibility in measuring loads. Case and point: last month I pulled 30 bullets the night before a big hunt and decided to re-measure my powder. I was loading H-4831SC, 60.0gr behind Hornaday 130gr (.277) bullets. I use a Redding powder dispenser to throw around 59 and change and "top off" the load with a trickler on my digital scale (brand X), whose reproducibilty is +/- 0.1gr. I routinely re-weigh the tray until I get 60.0gr 2-3 times in a row.

Well guess what .......when I re-measured those charges I was getting 59.9gr and 60.1gr among the 60.0gr loads.

I remembered reading this thread and did a web search until I found the digital scale I wanted. It's reproducibilty is +/- 0.01gr. It is a Tanita 1210-100. Apparantly this is a jeweler's portable scale that weighs up to 100 carats (hence the "100" in the model number). I believe it'll weigh up to 20g, or 380gr. The only drawback is it takes 6 AAA batteries, but I've already soldered the wires from a 9v transducer to the battery terminals and it works like a charm.

I used to use those old Mettlers in college and med school....kinda big, huh!

Anyway for around $200 (not much more than an RCBS or PACTS scale, you can find a scale that's tenfold more precise, compact and potable.

P.S. I love your book!

The part of the debate that you are not addressing is that of volume VS. Weight. Some shooters that are interested a less than a minute of accuracy at 1000 yards are more interested in having equal volume than exact weight. How do you explain that?

Frank,
There is a possibility that using a transformer (not a transducer) may affect the accuracy of your scale.
Most transformer/battery eliminators have a large amount of AC noise. Also their DC may be very "choppy", instead of a consistent DC level as provided by a battery.
You MIGHT have turned a very accurate scale into a average one by trying to save a few cents on batteries.

Bill,

Good point regarding the "dirty" DC that usually comes out of a transformer. There is usually a high amount of ripple coming out of them. They are used quite often as a supplement to, or to charge the batteries in a device. When used as a "battery eliminator", the device will have a filter circuit to clean up the ripple. In the case of rechargeable batteries, the batteries themselves will filter out quite a bit of ripple. To make a long story short, if a device is designed to use batteries only, use batteries only. If it was designed with a external DC source as an option, there would have been a jack to plug it in to.

Jeff