Reloaders -- BEWARE!

Do you think a few molecules rubbing off my check weight will affect my loading scale that is only accurate to .1 of a grain?
I don't think I have anything to worry about when the equipment I'm using (scales with an accuracy rate of +or - .1 gr) has a variance of weight a million times more than the molecules weigh that is rubbing off my check weights.

That is the least of my worries.


Yes, this is mentioned in some degree of jest.
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I would hope so.
 
Well I figure it this way. Does any of the error mentioned come in light of the intended use of any of my powder weighing scales? Following careful thought and consideration the answer is nope. :)

Actually this is not the first time that standards of measurements have come up for changes and it won't be the last. The calculations based on fundamental constants has been the direction other standards have taken so the kilo gram change would not really surprise me.

Ron
 
That's why they make 'standards weights', traceable to NBS standards. They're not that expensive.
 
My balances can only reliably measure to 1/10 of a grain. A few molecules here or there have no effect.

As I was once told in college, the difference between Engineers and Physicists is that Engineers have the luxury of being able to look at the equations used to describe physical systems and decide that various parts of the equation do not have a meaningful impact on the computations. This is one of those times.
 
hdwhit said:
As I was once told in college, the difference between Engineers and Physicists is that Engineers have the luxury of being able to look at the equations used to describe physical systems and decide that various parts of the equation do not have a meaningful impact on the computations. This is one of those times.
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The joke I heard was a physicist, a mathematician and an engineer were taken out to the 50 yard line at local football stadium. At the end zone was the college's cheerleaders, and they were told that they can run from the 50 yard line advancing half the distance to the goal line each minute. If they make it to the goal line they will be able to date one of the cheerleaders. The physicist and the mathematician scoffed, but the engineer started running. The mathematician yelled at the engineer "What are you doing you will never reach the goal line?" The engineer replied "I can get close enough for all practical purposes."
 
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Kinda like theory vs. real life. Not one of my 4 reloading scales is "laboratory accurate", but they check well against some of my standards (new coins, check weights, premium bullets). Besides, the reloading scale need not be accurate to one hundredth or even one tenth of a grain, but it should be repeatable to .010 grain...
 
I'm presuming this to be a tongue-n-cheek kinda thread. :p

But speaking of check weights:

I always use them to calibrate my balance scale - every loading. I calibrate to the nearest 0.5 grain to the load's charge weight. i.e. if my charge weight is 5.8 grains, I'll calibrate to 6.0 grains.

AND - I never touch my check weights with my bare hands. Hand oils are corrosive (especially mine, for some reason - if I touch a piece of copper, there will be my finger print the next day). I usually wear gloves when I load (mostly because my corrosive hand oils will tarnish my just-tumbled shiny brass); and I always use tweezers (gloves or not) to handle my check weights.
 
AND - I never touch my check weights with my bare hands. Hand oils are corrosive (especially mine, for some reason - if I touch a piece of copper, there will be my finger print the next day)
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Do you eat a lot of spicy foods? I never where gloves and I have only one piece of brass that has my finger print on it and it took 10 years to show up.

Maybe I better check my pulse.
 
In the reloading world, I don't think a variation of "five parts in 100 million heavier than all the working standards" will keep me up at night worrying about my checkweights....
 
The change away from physical standards is, as Ron said, ongoing. It used to be a milliliter was defined as the volume of a gram water at its most dense temperature (a tiny hair below 4°C). That definition had precision issues because it depended on both accurate weight and accurate temperature measurements in combination. Later it was defined as the same volume as a cubic centimeter (a cube one-hundredth of a meter on each side) with a meter being defined as the distance light in a vacuum travels in 1/299792458th of a second. Prior to that, it was defined by a certain number of wavelengths of a krypton86 emission in a certain oscillating mode. Prior to that is was the length of a physical platinum bar. Prior to that, it was a ten-millionth of the distance from the equator to the north pole, a distance that isn't perfectly constant because the earth isn't a perfect sphere.

Well, but how precise are your check weights? Most of those sold for reloading are class 6. These are not the greatest precision available, so moving them out of tolerance by handling them is not easy. Class 0 laboratory weights are another matter.

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I have check weights, I have check weights that do not agree with each other, I guess I should expect that with anything associated with reloading.

I also have check weights that are what I consider expensive and I have check weights that I consider cheap. SO:confused: I called a company that sells check weights, they suggested I use the small tweezers when handling the check weights and the cost of the weights had to do with the material used to make the weights. And I was surprised.

F. Guffey
 
I would think lack of a perfectly level surface, microscopic film on the rollers, or residue build up on the beam, pan, or hanger would have more effect than a few missing molecules on the check weights...

I will file this in the appropriate place... file cabinet #86.
 
I reloaded safely with just Lee dippers and no scale, back in '69 when I was hard pressed for cash. I thought my loads varied as much as .25-.5 gr., but when I got a Lee Safety Scale I found I could actually hold .1 gr with dipping W231. Now my scales are much, much more precise (one weights to .010 gr.), but my 38 Specials of '69 were/are just as accurate and safe as my 38 Specials of today, using a digital scale calibrated in .010 grain... :D
 
""That's why they make 'standards weights', traceable to NBS standards. They're not that expensive.""

Well I'll tell you - the older balance scales used in the old pre 1970's chemistry classes - what many people don't know is that those calibrated weights were sometimes pure platinum.....

Not expensive he says........ keep an eye out for me for old scales at yard sales - I might pay you to ship them to me......
 
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