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Which Scale Check Weights?

First criteria should be 'Sameness'. Long term sameness.
A precision mass standard is only used to calibrate working standard, the ones you touch when calibrating everyday devices.
Precise standards are made from a non-magnetic (or nearly so) Stainless Steel and are reported with respect to
'apparent mass vs a stated density' at standard conditions. It used to be App Mass Vs Brass, and when changing bases a correction is required.
Find a mass that isn't susceptible to nicks and scratches or corrosion. A FMJ bullet if protected from abuse would be fine for a 'test weight'. I use this for my 22 Nolser loads around 10 carats or so. I think I know the weight of this 'adjusted dime' to at least +/- 0.002 grains.
GrainExperiment.jpg
Also remember that when comparing two equal or nearly equal weights, the balance/scale is basically an uncalibrated substitution device. Weigh a 31 grain test weight, weigh 31 grains of powder. Should indicate the same (except for high precision work with materials less dense than the test weight).
For a scale that can weigh to 1500 grains, and your target weight is 30 grains or 80 or 150, then a test weigh near those values would be best if you want to have confidence in your measuring process. You were probably sent a 50 gram or 100 gram weight. That sets the full scale value which is likely never used. If 30 grains indicates 30.05 grains (indicates high) then you could even pad your full scale calibration to get a more accurate reading at lower values.
If you buy a cheap weight like off Amazon or Ebay, expect it to be Chrome Plated Magnetic Steel. Sort of OK.
Accuracy grades of M1, or even M2 would be adequate for all but the most anal reloader :)
If you bought a 'Set' with multiples of 1,2,2,5 or 1,2,3,5 then combinations can be used as a confidence check for any single weight.

Sure a tenth or two grains isn't gonna matter much at all but with a little attention to technique is will be so far into the noise that it WON'T MATTER AT ALL. Buy that $$$ 0.02 grain scale, a full scale cal weight, and a check weight near each of your most common/important values.
EX-NASA Senior Metrologist (not the weather kind)
 
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The US government manufactures check weights in a variety of sizes suitable for reloading, https://www.usmint.gov/learn/coin-and-medal-programs/coin-specifications. The one on the left gives the best bang for the buck.
The U.S. Penny?
Until you have a tolerance for that best bang for the buck test weight that costs one cent, that 2.5 grams (38.58 grains) might not be worth the cost for precision weighing.
For example, IF the weight tolerance (expect the average to be close to 2.5 grams) is +/- 0.019 grams (almost +/- 0.3 grains) that doesn't sound all that precise to me. But, it was cheap :)
Using a brand spanking new penny to check a powder charge around 38 grains and you could be off 0.3 grains.
Probably better than that. Maybe withing a tenth of a grain, unless you got a light or heavy one. Then probably still within +/- 0.2 grains. Unless you were really unlucky.
You could weigh a couple hundred pennies and pick one from the middle of the distribution and keep it as your check weight. Make sure they are all nice new shiny pennies though. I use a reduced weight dime, 35 grains thinned to 31 grains (just for the fun of it).


Maybe you could use your +/- 0.1 grain Chargemaster to check the weight of a penny, then use the penny to check the Chargemaster.
Then use the Chargemaster to check the penny, and then the penny to check the Chargemaster, and then - - - :)

Isn't it sad to think 7 pages of posts are only worth one cent :)
 
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Danny,
Why not? A 2 gram check weight (10 carats) works great to check my 30 to 31 grain loads.
Carats? :confused:
Yup. My cheapo digital scale that I use most reads to 0.02 grains, 0.002 grams (sold as 0.001 gram resolution), but reads to 0.005 carats which IS 0.001 grams so I guess it's not that big of a lie.
I have a brass grain/gram set but still mostly use gram/carat.
EDIT: Gram check weights might not be best for a grain beam scale.


Oops
looks like my next post was flagged as spam
This message is awaiting moderator approval, and is invisible to normal visitors.
Not a problem, I'll follow the rules.
 
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If shopping, look for at least tolerance class M1.
A M1 class 2 gram weight is +/- 1.2 milligrams, 30.864 grains +/- 0.0185 grains
A M1 class 5 gram weight is +/- 1.5 milligrams, 77.16 grains +/- 0.0231 grains
Remember the penny?
2.5 grams +/- 19 milligrams, 38.58 +/- .29 grains
 
If a check weight is only used to check that the device is getting the correct answer, then as noted ad nausea it doesn't matter much. On the other hand, if the weight is used calibrate a digital scale then it should be as accurate as the user requires. Something to consider, you may be better off using the check weight to confirm accuracy vs calibrating more frequently as the act of calibrating also has error associated with that operation (eg the precision of weighing). At least that is what we found with a number of instruments that we used.
 
If a check weight is only used to check that the device is getting the correct answer, then as noted ad nausea it doesn't matter much. On the other hand, if the weight is used calibrate a digital scale then it should be as accurate as the user requires. Something to consider, you may be better off using the check weight to confirm accuracy vs calibrating more frequently as the act of calibrating also has error associated with that operation (eg the precision of weighing). At least that is what we found with a number of instruments that we used.

There is a term in metrology for precisely that. Tampering.
 
The original post was in January. I made my standard for free out of stainless steel. All I want to use it for is to adjust my zero on the beam. It's a piece of metal and it's weight doesn't change. I weighed it at work to at least 4 decimals. Repeatability not accuracy. If it's an electronic scale the same deal does it weigh what it's supposed to be?
 
Kind of funny how things that sound hard sometimes get answered in a post or too, but some simple-sounding topics like this thread about a hunk of metal just keep chugging along.

What is the best check weight if you’re loading for a 6.5 Creedmoor?
 
The original post was in January. I made my standard for free out of stainless steel. All I want to use it for is to adjust my zero on the beam. It's a piece of metal and it's weight doesn't change. I weighed it at work to at least 4 decimals. Repeatability not accuracy. If it's an electronic scale the same deal does it weigh what it's supposed to be?
I would like to buy some various weights from you.
 
i need to buy a GOOD set of scale check weights. Please throw some options at me as to which weights are accurate and reliable.

Also, let me know which weights you would not recommend due to inconsistency of weight.
i need to buy a GOOD set of scale check weights. Please throw some options at me as to which weights are accurate and reliable.

Also, let me know which weights you would not recommend due to inconsistency of weight.
A very entertaining (and a little old) thread.
 
I bought a cheap set off ebay. They are as precise as the weights that came with my ChargeMaster.

I'm not too concerned about an inert chunk of metal somehow becoming unreliable. Am I missing something?
I made my own weights at work out of stainless steel and weighed them on a very accurate lab scale. There is no need to weigh accurately. You just want to see if the scale weighs the piece of metal the same each time. before use.
 
Over a decade ago, for a brief time I was able to borrow a milligram scale of decent quality. While I had it I weighed a number of coins of different denominations and put them and a list of their weights in an envelope in the drawer where I keep my 10-10 scale. At the time, I checked the weights on my scale and they were very close, well within my need for precision. As a practical matter,I do not need to weigh powder to the granule and I generally use one scale for all loading. As long as it gives the same result for multiple weighings of the same thing, and that weight very close to correct, I am good to go.
 
Checking reload scales for consistency only is a bit like bathroom scales without a graduation. 1lb is 1lb.
It depends on your needs.
 
Renewed interest in this old thread has peaked my interest again :)
My current good scale is a A&D EJ-54D2. I use it in gram mode as my cal/check weights are in grams.
The math isn't that hard.
On the low range 20grams or so the software allows you to perform the calibration at any 'Full scale' value.
I use 10 grams as that covers my bullets, cases, powder and primer. I check at 1 and 2 grams.
My check weights are pretty good, ASTM Class 1, which is better than needed by a long shot.
The scale (on the low range) counts by 0.0002 grams, and typically will repeat to 0.0004 grams (2 counts).
Again, better than needed. I take extreme care in setting it level (to the built in spot level). Re calibration (@ 10 grams) is seldom needed, just a warm up, zero and go. Since I don't have a temperature controlled lab zero can be an issue. Instead of using the software Auto-Zero (turned off in software) I do have to rezero/tare every so often likely due to slight temperature changes in the room.

I sure this thread will pop up from time to time over the next few years :)
 
Nothing is wrong with them.
In fact comforting to have them .
Tell me about that old scale in the picture, very cool
Ahh Jim, the old scale in the picture would more properly be called a balance, it doesn't weigh anything. You need to zero it using a known mass. This particular one was made by Pacific, and at a total guess, probably dates from the 1950's. It's not damped in any way and just so simple there's very little to go wrong.
The balance was supplied with a set of grain checkweights, including some little 10th gn weights.
I also have another of this type, also Pacific, oil damped, I would guess of a slightly later date.
 

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