Scales not the same?

[darchell]

I ahve two powder scales. One is a RCBS 505 beam scale and the other is a electrice RCBS powder master. When I weigh charges they are always different by .1 grain. THe beam scale shows either one over or below the electric scale. I have balanced them several times and they both show that they are accurate. Which do I beleive? any suggestions?

[Rick in Oregon]

I've seen similar readings with my Dillon electronic scale and my time-proven Ohaus single beam unit. Considering you are talking about only .1 grain difference, chalk it up to minor friction differences, air currents in the room, static charges, magnetic influences, or any other number of infinite variables that could exist. Chances are the electronic unit is spot-on, although mine needs to be zero'd quite often, so I use and trust my beam scale more often than not.

I'd not spend too much time fretting about the difference unless you're loading for very small cases where .1 grain really starts to matter such as the Hornet, Bee or like size cases.

[darchell]

Thanks for the quick reply... I am loading the .204 Ruger. The weird thing was that I would measure first on the digital then the beam. One load the beam would show .1 grain heavier and the next it would be .1 grain lower. They were both right on accurate though with the same load. Meaning as many times as I would go back and forth the numbers would not change. I like the digital for the obvious reason it is easier to read. Thanks for the reply.

[futuretrades]

if you check the manufacturers specifications on any scale i know of, they say the scales are accurate to within .1 grain. this may be the reason for the difference between the 2 scales. just make sure you calibrate your electronic scale each time before you start loading. or you can take your calibration weights and double check each scale with the same weight. i have both scales myself and i started double checking my electronic scales with the 505. what i found was that my electronic scale was within.1 of the manual also. i am not loading for match shooting, so i don't recheck as often, because i have learned to trust my electronic scales. that is not to say i never check my electronic against my manual scale , i just don't do it near as often.

[darchell]

I am starting to think I should have stuck with not checking between the two in the first place and not given myself this headache. WHat's the old saying, what we don't know won't hurt us. I guess if they were three grains off that may

[Rick in Oregon]

If either scale came with "check weights", now would be a good time to test each scale to see which one is dead-nuts, and which one may be off just a tad. My Dillon came with such weights, and it's good to have a benchmark for such tasks.

[darchell]

I checked the digital can't check the balance. The weight for hte digital are heavier than the balance will allow.

[acloco]

Flux capacitor is reverse biasing the dielectric core of the magnetic aura field on the beam scale.

Trust me....it takes a LOT of Reynold's brand aluminum foil to fix this problem.

RIO walked you around the problem, future gave you the book answer, and RIO sent you back to your wallet.

[jo191145]

How about just repeatedly weighing a 32 gn bullet on both. Write down the inconsistencys and average it out.

[Fatman]

I agree, about every fifth round, I'll check my scales with a 32 grainer, then a 52 grainer just for a quick check.

[darchell]

I like the bullet idea. I will try that as soon as I get down to my man cave

[Va varminter]

If you can't see a difference when shooting at paper or fur who cares. I did have a Hornady beam scale that was really fudged up. But it was off by well over .1 grain.

[Hawkeye Joe]

Why speculate when you can easily get the facts. RCBS makes a nice little set with anvils and rods as light as .1 grain. Scales can be tricky little critters that's for sure. My Hornady electronic scale was one of them. I now use a Acculab scale and my only complaint is it might be off by .02 grains....Yes .O2. I had a .02 grain piece of dust for a check weight but I lost it.

[kenbrofox]

Hi Mike, my wife found a .02 grain of dust when she was cleaning, not sure if it's yours but i will post it off to you if it's any use to you KB.

[Wrangler John]

What you are seeing is the variance between two modalities of measuring. This is quite common in laboratory and process controls. For example, a sonar flow meter that uses a Parshall or Palmer Bowlus flume for determining flow by depth (head) measurement will give a different measurement than an ultrasonic flow meter that uses Doppler or Transit Time measurement through a pipe of known diameter. Electromechanical flow meters that use paddle wheels or propellers will vary from the others. Usually this "error" is within the specified accuracy range i.e. +/- a certain percent or volume at a given flow. While the variation can be corrected electronically, small variances aren't worth worrying about except in certain applications where chemical reactions are involved.

Generally, electronic systems vary over time due to voltage, resistance and temperature changes, and may even vary as they warm up during use. Lab scales have to be absolutely level and in a temperature controlled environmental enclosure.

Now that I'm retired I don't have to worry about such things anymore, I just dump the powder into the pan and weigh. Close enough for government work.