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Powder scale headache...

Discussion in 'Handloading and Reloading' started by Gtimothy, May 22, 2012.

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  1. Gtimothy

    Gtimothy Member

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    I must be getting old or just can't understand what I'm reading. I'm trying to set up my RCBS Uniflow Powder Measure to throw charges for .223 cases. I'm using Hodgdon Benchmark powder and want to throw a 25 grain charge. I'm using a Lee Safety scale (I know...) to verify charge weight. Here's where I seem to be running into problems. I zeroed out the scale with an empty pan hanging from the beam. I set the ball and slider to measure 25 grains then rehung the pan from the beam. I started to throw charges and weigh them while adjusting the powder measure. I got the charge weight to balance for 25 grains but the amount of powder looks way too low in the case.

    I'm now at work and got to thinking about it and decided to have my wife do an experiment. I had her measure the weight of the charge on our digital postal scale (grams) then converted it to grains. According to what she told me, my scale is off by almost 10 grains!!!! Fortunately I only put together 20 rounds before I had to get ready for work but it has me befuddled that it could be that far off. I'm going to disassemble them in the morning and start all over.

    Beside the fact that my scale is cheap, ( so am I) is there any other trick to this thing that I need to look out for? I can deal with under charges but if this had gone the other way....:what: :eek:

    Thanks in advance
    GTC
     
  2. Certaindeaf

    Certaindeaf member

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    You need to buy some glasses.. and an RCBS 505.
     
  3. Gtimothy

    Gtimothy Member

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    I used to have a 505 years ago...sold all my stuff to fund a hobby. Wish I hadn't! Glasses were on. Senior moment perhaps?
     
  4. cberge8

    cberge8 Member

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    Assuming the Lee safety scale is sitting level, I would not hesitate to trust it.

    I would not, on the other hand, trust a postage scale to weigh powder charges.
     
  5. rcmodel

    rcmodel Member in memoriam

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    Take a known bullet weight from your box of .223 bullets and weigh it on the scale.
    Lets say it's a 50 grain bullet.

    At the very worst, the scale should read within 1 grain of what the factory says the bullet weight is.

    Then throw two 25 grain powder charges in the pan and weigh that.

    That will tell you right of if it's you or the scale off 10 grains.

    rc
     
  6. floydster

    floydster Member

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    Where oh where, is common sense in this thread, it scares me to no end when people like this reload.:rolleyes:
     
  7. T Bran

    T Bran Member

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    Make sure that the balance blade is in the correct position on the base of the beam it can be set in the wrong spot and still function but will be way off. The other thing about beam type scales is they must be on a perfectly level surface.
    I use the Lee scale for all of my rifle loads but do it a bit differently than most.
    First I zero the scale on a level place. Once I set and lock the scale to my desired weight. I then use a dipper that is just below the charge weight I want. Next I dip a scoop into the pan [which is still hanging on the beam] and trickle the rest of the load up slowly. I then remove the pan and pour the powder into the empty case and rehang the pan.
    If you have any doubts about your scale's accuracy buy and use a check weight which every reloader should have for safety regardless of what brand or type scale you use.
    The above is what I do for my hunting and serious ammo. For plinking ammo I use a low to mid charge weight and set the Perfect powder measure to throw the lower charge if it wanders a little I'm far enough below max that it wont really matter as I'm using pulled FMJ which arent exactly great in the best of loads.
    Hope this ramble does you some good and please buy a check weight.
    T
     
  8. Gtimothy

    Gtimothy Member

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    I still have 3 more hours of work but rest assured, I will figure this out! I appreciate the suggestions and may just have to bite the bullet and get another RCBS 505. I never had a problem reading or setting one of them up! I think the Lee is just too gimicky for my old self! Man I miss my three beam scale! :(
     
  9. Gtimothy

    Gtimothy Member

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    The "common sense" is where I realized something wasn't right and asked a question. Been reloading for a long time. Having to have to replace stuff I sold back in the 90's with this cheap gimicky scale comes with a learning curve. Once I get this figured out it won't be a problem and you can go back to "helping" other people with your vast knowlege. Off my soap box.
     
  10. Certaindeaf

    Certaindeaf member

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    Honestly, when I use mine, I get my face right close and square to it and use readers and a flashlight.
     
  11. rcmodel

    rcmodel Member in memoriam

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    And you will get it figured out.

    Lots of people on here have had "moments" with Lee scales in the past.
    I have never used one, so can't say.

    But it doesn't seem to be an uncommon problem.

    Once you "get it figured out", they are reported to be pretty accurate scales and should serve your needs just to double check a RCBS Uniflow.

    rc
     
  12. rfwobbly

    rfwobbly Member

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    Going by that description, it's not clear that the pan is in place or not during zero. Obviously, the pan and pan holder must be in place to zero. Make sure all the bob weights are also on 0. Then you can level the beam to indicate 0.

    If you are doing this correctly on the beam scale, then there is a greater chance of the kitchen scale being off by 10 grains because you are not working in its "comfort zone".

    Try this experiment....
    Four 55gr bullets should weigh 14.2 grams
    Three 55gr bullets should weigh 10.7 grams
    Two 55gr bullets should weigh 7.1 grams
    One 55gr bullet should weigh 3.5 grams

    I bet the kitchen scale wanders as the load gets lighter.

    Hope this helps.
     
  13. T Bran

    T Bran Member

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    Dont discount the Lee scale too quickly they are very accurate and I've read more than a few posts that state folks keep their Lee scales around to verify their electronic ones.
    I'm not saying it is the best ever devised but it has it's place on lots of benches.
    T
     
  14. Gtimothy

    Gtimothy Member

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    I only used the kitchen scale to verify the load was light. I wouldn't use it to load with. I was just trying to do a check my wife could do over the phone. As it was, a 25 grain load should weigh 1.62 grams. My wife said that the charge on a zeroed electronic scale didn't even go up 1 gram. This is how I verified the charge was light over the phone. When I get home I'll figure out where I went wrong with the Lee. Thanks guys for understanding!
     
  15. rfwobbly

    rfwobbly Member

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    I get that part.

    But the electronic scale has a LOT more ways to introduce error than the beam, and digital scales are especially noted for being erroneous at their extreme range of measurement. Since no one (not even my wife) measures 1 gram of food, this is not usually detectable by the user. But here you are trying to measure 1.62 grams.

    That's why I asked you to measure the bullets on the digital scale. You'll most probably see the error creep in when you get below 10 grams. In other words the error in digital scales can vary in different weight zones, so the error plots as a curve.

    If you do the same test on the balance beam, it may be off, but it will be off by the same percentage across the full measurement spectrum. In other words it will graph as a straight line.

    Here's a picture to explain the possible error in digital scales versus beam.....

    Scale.jpg

    Is this helping ?
     
  16. Gtimothy

    Gtimothy Member

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    I understand the way the electronic scale can introduce errors into the weight displayed. My purpose in using the scale was only for verification of a problem and know that the "actual" weight displayed by my digital scale is not accurate. I thought it was pretty clever of me getting my wife involved though! ;)

    I honestly have no desire to buy or use a digital powder scale. I have read the reviews and complaints about not being able to get a "zero". I only use powder scales to adjust the throw of my powder measure. After I get the measure adjusted and locked in I'll use the scale to prove the throw every 10 to 15 drops. As I said in the OP, I'm just trying to get ideas on what I might have missed with my LEE.

    Thanks for the info though!

    GTC
     
  17. ljnowell

    ljnowell Member

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    There is nothing "gimicky" about that scale. I have been using one for years and its dead reliable. My guess is its a 99.999999% chance of a user error. In the world of mechanics you can always tell an inexperienced or unskilled guy, because he blames the tools, dont be that guy.

    I am not trying to rip you either, Im sure you know what you are doing, but bashing the "cheap" scale that has worked for God only knows how many other people perfectly makes you sound whiney. Let us help you, but dont give guys a reason to not want to.
     
  18. wingman

    wingman Member

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    Double check instruction you may have scale setup incorrect or trying to zero without pan, basket in proper position,dusty area where it have accumulated on scale,is scale level, any vibration or air current in room.

    I have never used the Lee but I do use a Lyman balance beam and my main scale is a digital RCBS750, I cross check between the 2 and never have a problem.

    As someone suggest weight a bullet, like any tool takes practice.
     
  19. FuriousGeorge

    FuriousGeorge Member

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    I had a Lee scale that came with a kit and also bought an RCBS scale later. Both scales at one time or another did what the OP had described. What fixed it for me was 1) making sure the scale was on a level surface, and 2) removing any dust or dirt that may have settled in the area where the beam balances.

    One other tip on "level" surfaces... You "level" surface doesn't *need* to be flat in both the X and Y directions. As long as it's flat in one direction, you can still orient the scale with the beam parallel to the non-flat direction and use the scale's feet to level the beam. I hope that makes sense. :)
     
  20. Gtimothy

    Gtimothy Member

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    OK, I'm home now and found what the problem is. There are two "0" positions on the "grain poise" (slider) and I zeroed to the wrong one which is why the weight was 10 grains off. Operator error on my part, design flaw on LEEs. I've learned from my mistake and it won't happen again. Thanks for the help and the criticism.....the shows over you can all go home!

    I have some bullets to pull....:banghead:
     
  21. MEHavey

    MEHavey Member

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    ;)
    We all start somewhere.... And the OP is asking the right people. :)

    That said, the best suggestion so far is to use a known bullet as a starting check weight. The really best thing would be to pick up some actual check weights and check the scale as near as possible to the desired powder weight as you start.
    http://www.midwayusa.com/product/612694/lyman-scale-weight-check-set

    Best of the best... see if you can find one of these on E-Bay:
    http://www.ecrater.com/p/13949323/texan-304-reloading-powder-scale

    I've had a lot of scales over the years (incl the current wonderful RCBS ChargeMaster) but the old Texan remains the True Cross
     
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