Beam scale predicament question

[PracticalTactical]

For all your extensive experience, you seem to have been very unlucky with your encounters with beam scales.

It's not that I have been unlucky. Its that I have a reliable method of validating. If you don't have it, you just wont see the difference.

 

[1066]

It's not that I have been unlucky. Its that I have a reliable method of validating. If you don't have it, you just wont see the difference.

I think you underestimate beam scales, especially when used in conjunction with certified checkweights.
If you take, what was probably the simplest reloading balance every made, the old Pacific balance, you would see that weights much less than 10th grain can easily be resolved and repeated consistently, especially if used with some optical enhancement, camera, phone etc.
If you place checkweights to your desired powder charge in the pan and zero the balance, every subsequent charge will be the same within a kernel. A single kernel of something like Varget is about .02gn, if you were to add 5 kernels to the pan you would have a clearly visible deflection of 1/8th inch or more.


A digital scale may be quicker and more convenient but there are plenty of accurate reliable beam scales about.
I have a beam balance that resolves to .1mg (0.00154gn) and yes, it can also weigh the difference between individual between kernels.

 

[M-61]

I have an RCBS 304 (Oahus) Bought it new many tears ago. Never failed me. What I’m looking for is consistency. If the numbers are set to say 20.8 I want that to happen each time . It’s a triple beam dial a grain which sounds great and actually it is
(For me)

 

[PracticalTactical]

Our tuned beam scales resolution is much closer to .02 or 1 kernel of Varget..

Sorry, but I simply don't believe it. I have done this many times and my verification scale is ten times more precise than the one used in the video. I can only assume the data samples are cherry picked and are not typical of a wide sample size.

One kernel accuracy from a beam scale is simply an unrealistic accuracy expectation.

But hey, if you are happy with it, by all means use it.

 

[BoydAllen]

Sorry, but I simply don't believe it. I have done this many times and my scale is ten times more precise than the one used in the video. I can only assume the data samples are cherry picked and are not typical of a wide sample size.

One kernel accuracy from a beam scale is simply an unrealistic accuracy expectation.

But hey, if you are happy with it, by all means use it.

The main limitation of beam scales is how little the pointer moves with the addition of small amounts of powder, and how well they repeat. In the video the trickler is controlled by an "electric eye" that senses the beams position, so that issue is removed. In this case the issues become how well the scale repeats and the resolution of the switching system. I agree that a larger sample would be called for, but I doubt that anyone would want to watch a video of 100 charges being trickled. I have one one of the Dandy tricklers that is controlled the same way, but I have put off testing it mostly because charge weight is not as critical for the distances that I shoot. Perhaps I need to get busy and do the test. In the mean time I would like to hear from anyone who already has done it. To get an idea of how a scale repeats simply pick up the pan and set it back down on the scale repeatedly, noting where the pointer position is each time. The same test works for digital scale to see if the reading is the same. For starters, twenty reps will usually show if there is a problem.

 

[1066]

The main limitation of beam scales is how little the pointer moves with the addition of small amounts of powder, and how well they repeat. In the video the trickler is controlled by an "electric eye" that senses the beams position, so that issue is removed. In this case the issues become how well the scale repeats and the resolution of the switching system. I agree that a larger sample would be called for, but I doubt that anyone would want to watch a video of 100 charges being trickled. I have one one of the Dandy tricklers that is controlled the same way, but I have put off testing it mostly because charge weight is not as critical for the distances that I shoot. Perhaps I need to get busy and do the test. In the mean time I would like to hear from anyone who already has done it. To get an idea of how a scale repeats simply pick up the pan and set it back down on the scale repeatedly, noting where the pointer position is each time. The same test works for digital scale to see if the reading is the same. For starters, twenty reps will usually show if there is a problem.

This is a well-produced video from a respected source. Although it's in the German language, you can pull up an English translation or simply turn off the sound altogether.

He is testing an auto-trickler with an RCBS 10/10 scale. At around 4.50 into the video he shows a chart of the charges measured when checked with a digital analytical lab scale.
In the chart on the left, for 20 consecutive charges, there is an ES of .06gn or three kernels of Varget.
This is an "off the peg" 10/10 performing as it should.

Interesting to see you have a Dandy auto-trickler Boyd. I designed and made the prototypes of the Omega auto-trickler for Dandy back in around 2010.

 

[PracticalTactical]

To get an idea of how a scale repeats simply pick up the pan and set it back down on the scale repeatedly, noting where the pointer position is each time. The same test works for digital scale to see if the reading is the same.

Scales can respond quite differently to a full load vs a slight incremental load change.

 

[BoydAllen]

Scales can respond quite differently to a full load vs a slight incremental load change.

For me it is important to know that a scale is sensitive enough to show the smallest additions of weight. They all respond to larger amounts. For beam or digital, I want to know if that response is consistent. Fortunately testing this is easy.

 

[sparker]

I charged 50 cases yesterday in 22 minutes. Including set up time. Charge weights read like this:

 

[Jon Leary]

My RCBS 1000 works well and consistently but I did notice one thing. My scale is at eye level for ease of reading. Consequently, you have to raise the pan up to eye level in order to set it on the support tray. It’s easy to tilt the pan when doing this. On a couple of occasions, I have noticed a couple of kernels laying in the support tray. If you don’t catch this, it will cause variation in subsequent loads. I follow all the sage advice on maintenance and storage of the scale, posted by these great shooters.

That is the problem with the pan support on most beam scales. If a few kernels fall out of the Trickler while the pan is removed and are not noticed right away then what? I replaced the pan support with a heavy piece of wire that was the exact same weight and now any stray kernels are not a problem.

 

[LC Tikka]

Clean all contact surfaces and spray with a no-residue silicone, pan hook & hinge included.