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Thread: Calibrate Scales

  1. #81
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    Quote Originally Posted by 1hole View Post

    Reloaders really don't gain anything with highly precise accuracy of a weight, what we do benefit from is precise repeatability so we can KNOW that a cartridge made today will be identical to others made six months ago ... that is, IF we are using exactly the same cases/bullets and powder/primer lots, which seldom actually happens.
    Some of us have several places to reload. I might do single stage 44 mag in one house and then another day on a progressive in another house. Same load.

    It's good to know the scales read the same.

    Like calipers and micrometers. I have a machinist friend who calibrates my good micrometers. I have miced and verified my NOE expanders so I can use them to quick check some digital calipers. Or as pin gauges,whatever.

    Maybe OCD but I find it easier to know actual numbers.

  2. #82
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    Quote Originally Posted by Petander View Post
    Some of us have several places to reload. I might do single stage 44 mag in one house and then another day on a progressive in another house. Same load.

    It's good to know the scales read the same.
    Everyone should do whatever takes to make them comfortable BUT, if they're using the same scale in different places and zero it in each place and it will weigh exactly the same.

    Variations of .1 grain or so, one way or the other, between different scales are meaningless unless the charges are on the ragged edge of disaster. In some 50 years of reloading with my own three scales, and with those of a few others, I've never seen any (clean) beam scale further "off" than that unless it has been visibly damaged. (Now for these digital thingies, they're a different ball of wax and I don't use them for powder!)

    For anyone using different scales in different places it would certainly be good to insure they all read the same, or nearly so. If they don't, just pick one scale as the standard and use it as a guide for the other(s). But it's hard to believe there could be enough difference between undamaged scales to be hazardous; anyone loading that close to a KABOOM is already loading much too hot! IMHO.

  3. #83
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    This thread has been a comfort to me. I have been loading on the Dillon 550B for several days for relatively short periods of time. Sometimes I will skip a day. No matter the interval, when I start up again with the same load, the measure throws a slightly heavier charge. I've checked and the difference is never more than .3 gr to .4gr. But for a charge of 4.3 gr in .45 ACP that I'm loading for my son I don't want to take a chance. I double check with the check weights for a setting close to the 4.3 charge, in this case 4.5 gr. The scale passes the test every time. I'm completely in the dark why the first 3-4 charges are greater than the following ones because it takes those throws to settle down.
    John
    W.TN

  4. #84
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    You've received many very good bits of advice. Here's mine and worth every penny you paid for it.......

    My wife bought me my first electronic scale for Christmas several years ago. It was an expensive scale and I set it up per the instructions. While using it, I noticed variations on the order of .2 gr. at times (using Pacific check weights). I would re calibrate and try it again. After several attempts I got frustrated, put it back in the box and went back to my balance scale. Because of my experience, I look on electronic scales with a jaundiced eye. Probably not fair, might have been my technique, but the prejudice remains. I never mentioned it my wife by the way..........

    Grab a paper clip, go to the drug store and have them weigh it in grains for you. Make a note of the weight and use it to check your scale periodically. Just don't misplace that paper clip!

  5. #85
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    Quote Originally Posted by alamogunr View Post
    This thread has been a comfort to me. I have been loading on the Dillon 550B for several days for relatively short periods of time. Sometimes I will skip a day. No matter the interval, when I start up again with the same load, the measure throws a slightly heavier charge. I've checked and the difference is never more than .3 gr to .4gr. But for a charge of 4.3 gr in .45 ACP that I'm loading for my son I don't want to take a chance. I double check with the check weights for a setting close to the 4.3 charge, in this case 4.5 gr. The scale passes the test every time. I'm completely in the dark why the first 3-4 charges are greater than the following ones because it takes those throws to settle down.
    I have noticed that the first few charges may be heavy at times if the measure has set for even an hour or two , so drop two or three when starting back up and return them to the measure or even if I have been messing with something on the press that might make it settle just like I would when settling the measure in after filling or making an adjustment on it , measures seem to be sensitive to any variance in routine some powders are worse than others.

  6. #86
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    Quote Originally Posted by onelight View Post
    I have noticed that the first few charges may be heavy at times if the measure has set for even an hour or two , so drop two or three when starting back up and return them to the measure or even if I have been messing with something on the press that might make it settle just like I would when settling the measure in after filling or making an adjustment on it , measures seem to be sensitive to any variance in routine some powders are worse than others.
    I just responded to a PM from a member here that has given me good advice in the past. He also recommended throwing a few charges back in the reservoir and checking before charging a case. I'm making that a regular part of my routine from now on.
    John
    W.TN

  7. #87
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    While I dont think its as important to have a scales thats dead exactly on a given weight. Reason being that a reloader works up to a given load with his scales and equipment so weather its 40.1 40.2 40.3 as long as it always the same scales and equipment. What I believe is important is that the scales resolution is so the 40.1 is always 40.1 when weighed. even a .05 variation in this aspect is .1 grn making that trickled with in a .1 charge of 40.1 charge a spread of 40.3.

    One thing done whe certifying an measuring tool is measuring the same item 10 times or more to prove this repeatability. Carefully weigh the same weight 10-20 times and see how your scales repeats then use a heavier weight and repeat. dust rounded damaged knife edges will have an affect here even bad or worn dampening.

  8. #88
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    Quote Originally Posted by country gent View Post
    ....even bad or worn dampening.
    Liquid damping (oils or water water) are indeed subject to errors induced by surface tension. Thankfully, magnetic dampened scales have no such sensitivity.

    Gunpowders have powdered graphite to lubricate their flow. A column of powder will slowly settle into a slightly more compact mass while just sitting thus the first few dropped charges are usually a bit heavy. Easy fix; quickly drop and dump the first half dozen charges back into the measure and then go on.

  9. #89
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    Quote Originally Posted by country gent View Post
    I may at some point make a balance scale from scratch in the shop. .... possibly water or light oil dampened.
    Dampening with a liquid would defeat your .02 gr. purpose. Surface tension on the paddle would destroy the kind of accuracy you hope to achieve. Use standard magnetic damping on a copper vane instead, there is no magnetic effect on the copper vane when the beam isn't moving.

  10. #90
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    I went down a very deep rabbit hole checking scales for accuracy. Purchased a very nice vintage set of check weights. Purchased 20 or so different balance beams and 3 electronic scales. What I learned was this, reloading quality electronic scales are not as accurate with lighter charges. Trickling light charges is an exercise in futility. Even some beam scales are not accurate through the whole range but with light charges and trickling they are more accurate then my electronic scales including the Hornady and RCBS dispenser/scale combo. Large charges were acceptable. I will not load light charges on any of my electronic scales. Check weights are essential for me but are only used once to verify a new scales accuracy. Once satisfied they get put back away..... the only way to learn is by doing...... No such thing as free education.
    "It is better to die on your feet than to live on your knees" Looking for an RCBS Ammomaster and H&R shotgun barrels regardless of condition

  11. #91
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    Quote Originally Posted by troyboy View Post
    Even some beam scales are not accurate through the whole range but with light charges and trickling they are more accurate then my electronic scales including the Hornady and RCBS dispenser/scale combo.
    I fully agree with your observations of flakey digital scales but I wonder how error you found any balance scale, at its worst. ???


    Large charges were acceptable. I will not load light charges on any of my electronic scales.
    I wonder, what are you calling "light" and "large" charges?


    Check weights are essential for me but are only used once to verify a new scales accuracy.
    Check weights are obviously the simplest way to confirm any scales absolute accuracy but I trust the maker's quality control system to do that. Therefore I use a few jacketed bullets to confirm that it's not massively off (i.e., perhaps as much as a full grain) and know that the beam calibration scale must insure the rest is also accurate ... I think.


    Once satisfied they get put back away.....
    There you go, once and done.

    The calibration of a mechanical beam scale, from one end of the beam to the other, is in the physical precision of the notches and they certainly are not going to drift over time!


    Bottom line, reloaders don't actually need high precision for charges, we need precision repeatability. I.e., assuming we use the same scale, if the charge we measure today is exactly the same as the one we weighed two years ago we're in good shape.
    Last edited by 1hole; 01-06-2021 at 11:11 AM.

  12. #92
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    1hole, light charges are pistol class with large being rifle. I can't remember if my results were posted or not. It really does not matter as my results were just that. Proved to myself what needed proven. Accuracy testing was not outside the realm of safety for reloading when the discrepancies were noted over the scales range. Incidently tuning the scales and the testing of sensitivity was also done. I wrote all this down prior to moving and have been on assignment for the last 3 years so I'm relying on memory without proper facts. I agree 100% with your statement but for me a scale needs to be accurate. Once satisfied that's what gets used. I also went down the die rabbit hole checking for concentricity, oal, etc but that is another topic.....
    "It is better to die on your feet than to live on your knees" Looking for an RCBS Ammomaster and H&R shotgun barrels regardless of condition

  13. #93
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    Quote Originally Posted by troyboy View Post
    I agree 100% with your statement but for me a scale needs to be accurate. Once satisfied that's what gets used.
    Of course we ALL want accurate scales but they are mechanical devices made to manufactoring tolerances so some variation is a fact of life. Thus, the question is, "How finely do we demand a powder scale's absolute accuracy?"

    I don't think a rifle charge (say 35 gr. or more) variation of +/- 0.2 gr. in absolute terms matters because at that level we're getting into the statistical grass variations in powder and primer lots, case internal volume variations, etc. And I doubt anyone has ever gotten a KABOOM from a variation that small.

    I haven't tested dozens of beam scales like you I but I have tested several and I have never seen one off more than .2 gr. at any point; they're rarely off more than half that. That's good enough accuracy for me IF the scale is totally repeatable - and I've not yet found a reloading beam scale of any brand that isn't quite repeatable unless it's bearing is dirty or it has been physically (and visually) damaged by a clumsy user.

    I worked several years as a precision electronic measurements tech in the space program. I do use a small (cheep) digital for weighing bullets and cases but I have not and will not use an electronic scale to measure my powder charges.

  14. #94
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    Just saw this thread. I will chime in, since this is what I do for a living.

    I work on scales, all sizes and shapes but small scales are my forte. I have one customer that uses RCBS 750 reloading scales in their manufacturing process, IIRC these scales come with a check weight and a button marked "cal" so they are easy to keep in line.

    If there is anyone on this board that is concerned about their scale I'd be happy to check it, all it would require is careful packaging and postage both ways. If you call your local scale service company chances are a visit or even if you drop it off at their shop for a look, will cost you as much as the scale. Currently our rate is $110 an hour.

    I live in Idaho, the elevation is approximately 2,300 feet. If you live on the Florida coast this can throw things off a bit, maybe .1 grain or so.

    All this being said, I'd be happy to help anyone in need, PM me if you need info or help.
    If your mind goes blank don't forget to turn off the sound!

  15. #95
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    Finding "nothing" to do one afternoon, I ran a three scale comparison through a series of check weights from 1 gram (15.43236 grains) through 33 grams (509.26788 grains) between well cleaned RCBS 5-0-5, RCBS 10-10, and Pact Digital scales. The results after 37 test weight increments (four of which were for determining whether each scale still read zero and zeroing - if required):

    NOTES
    A.) Testing ceased at 510 grains as the 5-0-5 had no further capability.
    B.) The 10-10 and Pact are capable of 1000+ grains.
    C.) The digital is FAST!
    D.) Damping of the pendulum in a beam scale is time consuming.
    E.) The 10-10 pendulum was 2X slower to dampen than the 5-0-5.
    F.) The 5-0-5 is the easier scale on which to dial a pre-determined weight.
    G.) The 10-10 had to be zeroed 3 times.
    I.) The 10 gram (154.3 grain) test was performed twice for all three scales.
    J.) Each scale is reported to measure within +/-0.50 grains by its manufacturer

    FINDINGS
    i.) There were 33 increasing weights measured for each.
    ii.) A total of 567 grams were weighed for each.
    iii.) Cumulatively, no scale was "in error"* more than 0.0135 grains (the digital was low).
    iv.) The 5-0-5 exhibited the least cumulative "error"* at 0.0020 grains (high).

    CONCLUSIONS
    1.) * ALL “errors” are attributed to ROUNDING.
    2.) All measurements were taken to one significant digit.
    3.) Actual grams to grains conversion was 5 significant digits.
    4.) These results are VERY ACCURATE and RELIABLE for my reloading purpose.
    Last edited by Land Owner; 01-16-2021 at 05:42 AM.
    If it was easy, anybody could do it.

  16. #96
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    Land, you give good scale accuracy info. While your sample base of only three scales is small your test results are quite similar to mine, with about ten scales tested over a period of about ten years, ending about 25 years ago.

    In several home moves, my records have been lost and my memory bank is broken, so I reported here that the max error rate I had found was less than 0.2 gr; your test figures jog my memory that my scale's error rate was actually only about a tenth of that.

    Not that it matters but your RCBS 505 and 1010 scales were made by Ohaus. My tests included scales from four makers but there was no accuracy difference.

    I believe all of the reloading scales tested by both of us were so good, so close to zero error, that concern over them is little more than a mental exercise in trivia.

    Bottom line, I'm comfortable using a single Sierra bullet as a confirming accuracy quick-check weight. Of course, business people are quite happy to sell anything, including costly scale test weight sets, to anyone willing to pay for them.

  17. #97
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    I had a Lyman scale , Lee scale and RCBS scale so I would check them against each other to make sure they were on. All three would measure for our purpose the same but the Lyman had the best dampening of the 3 and also had the small scale at the end of the pointer that I liked. The Lee had the least amount of dampening so I sold it along with a couple of presses. A friend did not have a balance beam scale so I gave him the RCBS he liked it so much that he gave me his electronic scale because he was not going to use it any more . When I tried to compare the electronic to the Lyman they rarely matched..... so I bought another electronic then I had 3 that didn't match .
    So at that point I bought a set of RCBS check weights and now have peace of mind but any thing of a known weight in the range you consider critical would work as well.
    Electronic scales are handy to have so I kept them , but I don't adjust powder measures with them, and has been pointed out they are useless to try to trickle into , at least the ones I have are.
    One more thing to keep in mind about scales is if you bump it or move it don't forget to zero it again before using .

  18. #98
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    Bingo ioon44! I couldn't have set it better!

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  19. #99
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    Yes, a good balance beam scale and my check weights have never let me down.

  20. #100
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    As to beam balances, I will quote an earlier post from USCRA112 : "Another factor can be the sharpness of the knife-edges on which the beam rests. They must be clean and sharp, and the anvils on which they rest must be clean, or you'll get some linearity error, and it won't be consistent across the entire measuring range."

    And add that the balance should be stored with the knife-edge OUT of the anvil to avoid wear.

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Abbreviations used in Reloading

BP Bronze Point IMR Improved Military Rifle PTD Pointed
BR Bench Rest M Magnum RN Round Nose
BT Boat Tail PL Power-Lokt SP Soft Point
C Compressed Charge PR Primer SPCL Soft Point "Core-Lokt"
HP Hollow Point PSPCL Pointed Soft Point "Core Lokt" C.O.L. Cartridge Overall Length
PSP Pointed Soft Point Spz Spitzer Point SBT Spitzer Boat Tail
LRN Lead Round Nose LWC Lead Wad Cutter LSWC Lead Semi Wad Cutter
GC Gas Check