Scales???

[Texanreloader]

Hey! It's me again. Still working on my 9mm/Titegroup loads. I have 2 scales RCBS 5.0.5 and a Lyman Digital 1500XP, neither one seems to be consistent w/powder measurements. I have zeroed the digital and the bar scale. I will measure out 3.8gr, dump it in the case, dump it back out on the scale and I get 3.4- 3.6 etc it's all over the place and no there is no powder left in the brass. (digital scale)
Confused and flustered!

 

[tightgroup tiger]

Is your furnace or air running. Even the slightest breeze in your room, that you don't even feel, can mess with your scales. Especially when both a beam and digitol are doing the same thing.
Take both scales to a different room and try test again. Just a suggestion.

 

[GeoDudeFlorida]

Hey! It's me again. Still working on my 9mm/Titegroup loads. I have 2 scales RCBS 5.0.5 and a Lyman Digital 1500XP, neither one seems to be consistent w/powder measurements. I have zeroed the digital and the bar scale. I will measure out 3.8gr, dump it in the case, dump it back out on the scale and I get 3.4- 3.6 etc it's all over the place and no there is no powder left in the brass. (digital scale)
Confused and flustered!

Believe it or not, this isn’t the first time that subject has come up: https://www.thehighroad.org/index.p...mation-busting-digital-scale-accuracy.759750/

 

[Rick Kr]

Digital scales can have a variety of foibles. There has been an interesting discussion over on the Accurate Shooter forum dealing with drift and a feature that some (most?) have which is an "Auto Zero" function, which can mask or hide drift. It is demonstrated how to set up a "Fake Zero" weighing some nice round number like 100.00 grains that moves the scale away from the zone where the auto zero functions so one can see when the scale has drifted. This "Fake Zero" is kept on the scale while weighing powder charges and the major unit (in my example above 100) is ignored when reading the powder charge.

I machined a piece of SS round bar stock and hit it just right, but another poster used a 100 grain bullet that did in fact weight 100.0 grn. In use, whatever container is used for weighing powder is Tared so the scale displays 0.00 and then the Fake Zero is placed so the display reflects the Fake Zero weight (in my example, 100.00 grn). Then the weighing can begin, noticing whenever the scale does not read 100.00 with no powder in the container. Doesn't change much, certainly nothing about the scales accuracy, precision or resolution, other than at least it is known when and how much drift has occurred.

Rick

 

[Blue68f100]

Get some calibration check weights to verify the scales. One thing I've learned on digital scales is if your using a pan, and zero with it on. Leave it on the scales at all times. Only remove to empty, then place it back. I do this with my GP250 and my RCBS CM1500. I have found if you do drift it's best to remove the tray, zero, place the tray back on then zero. I've noticed on the RCBS CM1500 if you don't do this it some times keep the old reference. This forces it to purge that part of memory.

Depending on powder used some can stick in the primer, through the flash hole. Tap on a hard surface will clean most but not all.