Getting single kernel precision cheap!

Discussion in 'Reloading Forum (All Calibers)' started by Evan, Apr 6, 2020.

  1. Evan

    Evan Gold $$ Contributor

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    I don't know why it didn't occur to me before today, but a balance beam scale can be much more accurate than you would think.

    I dug out my grandpas 5-10 beam and started checking my chargemaster lite with it.
    IMG_20200405_191459296.jpg
    I'd have the chargemaster throw a charge and I would transfer it to the beam. Zero the beam perfectly with that charge. Now check every charge on the beam to make sure they are the same without changing the beam weights. With my magnifying glass, I could easily resolve a single kernel up or down, which was all the chargemaster was ever off by. Pretty cool, if I do say so myself!
     
  2. rsmithsr50

    rsmithsr50

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    that is not "single kernel" accuracy, it is still plus or minus 0.1.
    design accuracy of the beam and the lite
     
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  3. 1066

    1066

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    Obviously depending on the powder but I find there are usually 4-5 kernels of Varget to a 10th grain, and single kernels are easily visible with a good beam scale fitted with a small usb camera.
     
  4. Evan

    Evan Gold $$ Contributor

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    Sure. I don't know where I am between 29.95 and 30.05gns (in this exact case), but that is different than knowing that all my charges are the same to within a kernel, which I would argue is the more important aspect. It's also with IMR4350 and not some tiny ball powder, so a single kernel is pretty heavy.

    If my chargemaster says it is 30.0gns, when I put it on the scale, it will be either dead on, or slightly high or low. Dropping in a single kernel or pulling a single kernel will get it dead on. If I then put it back on my chargemaster, it still reads 30.0gns. That's an improvement in chargeweight consistency.
     
    Last edited: Apr 6, 2020
  5. TheOtherZilla

    TheOtherZilla Gold $$ Contributor

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    I have a ChargeMaster and I hate it. I broke a small piece on my 50year old RCBS beam scale [same one in your photo] and couldn't find replacement part. Yesterday I got so frustrated loading 22 hornet with H110 that I ordered a new beam scale.. Probly gonna retire the Charge"Master".. I have only had it about a year..
     
  6. Evan

    Evan Gold $$ Contributor

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    I'm not bashing my chargemaster lite. It fixed my least favorite reloading activity: trickling up to charge weight. It has made it comfortable and pleasant to load 50-100 rounds of full quality ammo in a sitting. It used to take a couple hours to load 50. Now I spend maybe an hour per 50. This recent addition of the beam has slowed things down a little again, but I don't mind picking off or adding a kernel here or there; that's nowhere near as agonizing for me as trickling up. I really hate trickling...
     
  7. bozo699

    bozo699 Gold $$ Contributor

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    have you put a straw in your feed tube?... that really helps and there are some parameter tweaks you can do my cm throws pretty accurate I go a couple tenths low and trickle up with a omega on my gd503 it’s just about as perfect per charge as you can get
    Wayne
     
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  8. rsmithsr50

    rsmithsr50

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    no...you cannot tell xx.x5 on a xx.1 scale.
    you are between 29.9 and 30.1 when you are at 30.0 period.
    it is the limit of the scale.
    counting kernals does not improve the mechanical abilities of the scale PERIOD.

     
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  9. BoydAllen

    BoydAllen

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    Have you ever tuned up a mechanical reloading scale that was made by Ohaus, so that it comes to the same exact zero point no matter how you put the pan on, or used one in conjunction with a web cam to eliminate parallax and magnify the pointer and scale? My scale is a lot more sensitive and repeatable than when it came out of the box the first time, and I am not so much concerned with its absolute accuracy as long as it repeats well when weighing the same weight. can mechanical things be modified to work better than when they were new? Absolutely!
     
  10. Evan

    Evan Gold $$ Contributor

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    We may just have to disagree, but in case this is simply us not understanding each other, I'll try to explain myself differently:

    Gravity, a fine knife edge beam and a smooth bearing surface, and a sufficiently fine indicator of equilibrium do not have the limitations that electronic scales do for comparative analysis. I didn't set my beam to 30.0gns and then measure up to equilibrium. I had the Chargemaster throw a charge and then set the beam to equilibrate with that charge. I don't care if it was actually 30.04 or 29.97gns, I set it to equilibrate with that first charge. Every charge after was then made the same as that first charge by adding or removing single kernels to reach the same equilibrium.

    EDIT: I'll add that if you said, ok now go load 10 more today at the exact same charge weight, I wouldn't be able to. I took the setup apart. But in that reloading session, those are loaded the same.
     
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  11. Evan

    Evan Gold $$ Contributor

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    The pan base self centers my pan, but I checked this several times (maybe 5 ish) when I was first setting this up by lifting the pan all the way off and replacing it to make sure the beam repeated. With my magnifying glass I can see the wobble of the pan in the needle until it comes to a complete rest and the same weight returned to the same equilibrium across the several times I tried it before proceeding.

    Out of curiosity, Boyd, how would you recommend I go about further improving this beam? I'm nervous about stoning the knife edge, as I feel like getting the two knives off from each other would be more detrimental than any increase in their current finish. Are there other tricks I can try?
     
    Last edited: Apr 6, 2020
  12. rsmithsr50

    rsmithsr50

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    I may agree they were loaded the same.
    BUT
    YOU do not know what the load was
    NOR
    can you repeat the load.
    end of discussion.
     
  13. TheOtherZilla

    TheOtherZilla Gold $$ Contributor

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    Yeah, I tried. Can't find the right size straw. So I ordered a set of plastic inserts that are supposed to "fix" The problem.. And yesterday if I swung the plastic cover over it or moved it back the final charge weight changes.. I just don't trust this thing. I now have 50 rounds to tear down. Mine is sitting on a marble slab. Warm it up for at least two hours..
     
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  14. Evan

    Evan Gold $$ Contributor

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    At a certain point it makes sense to cut your losses. Especially if you don't trust it anymore. Most all of the complaints I've heard are about the Chargemaster, not the Chargemaster Lite, which is what I have. Once I got my lite on a battery supply and off the wall power, it's been noticeably more stable.
     
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  15. bozo699

    bozo699 Gold $$ Contributor

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    Take the cover off that’s a well known problem,... static. Fluorescent lighting affects them and a McDonald’s straw fits perfectly.
    Any breeze people walking around can effect them but mine settles down and is pretty accurate, but then I really just use it as a dispenser I transfer to a gd503 and trickle final charge with my omega.

    ps never turn it off I leave my scales in 24/7 and have them on a ups so if I lose short term power they don’t shut off.
    Wayne
     
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  16. redrockranger

    redrockranger

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    .1 .......much to do about nothing. Cabin fever ?
     
  17. TheOtherZilla

    TheOtherZilla Gold $$ Contributor

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    I'll try that. Damn cover is a nuisance. I'll also look for a ups .. I have a fluorescent light above my bench. I'll look to swap it out.
     
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  18. Evan

    Evan Gold $$ Contributor

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    I haven't ever encountered a viable node that was only 0.1, or even 0.2gns wide. I have seen compelling evidence that having all rounds in a group at the same charge weight (down to the kernel) is beneficial, thus why I presented this as an option to folks who maybe, like me, wanted to increase the consistency of their charge weights without spending much money (free for me, as I've had this beam around for a few decades now collecting dust).
     
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  19. Evan

    Evan Gold $$ Contributor

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    I run mine without a cover, but my room has no air currents, not even a furnace vent. I don't know how tolerant it would be in a "noisy" environment.
     
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  20. Hohn

    Hohn Silver $$ Contributor

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    I'd ask a different question: how much powder measuring precision is enough to where it's not limiting your accuracy potential?

    It's worth mentioning that 0.4 grains is only 1% of a 40gr short action charge. Even in .223, 0.1gr is less than half of one percent in variance. What makes a person so sure that this variation is more significant than other sources of variation? Do you have less than 0.5% variation in brass hardness? Case capacity? Neck Tension? Primer brisance? Bore condition?

    I think a lot of unvalidated assumptions underlie the desire for single-kernel levels of precision. If you can truly hold 0.1gr then I suspect that's more than adequate in most instances.

    BR guys have been shooting amazing groups for a long time before Prometheus and AutoTrickler and such expensive systems became available.
     

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