WHOA. Digital scale showing more than Safety Scale!

firemachine69

firemachine69

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Okay folks, I'm sure you're all getting tired of my incessant postings.

Same recipe as before:

IMR 4895
Wichester brass and primers (.308win)
Hornady Interlock BTSP 150gr.

I re-worked a new batch after my last failed attempt. Anyhow, I just picked up an MTM digital scale today, and find the readings quite a bit higher then what I'm showing on my Lee Safety Scale, and what I *think* (based on the safety scale) out of the Perfect Powder Measure. The Lee is being read correctly - so why is the digital scale off? It's on a flat, level surface (it wouldn't read otherwise), it's been recalibrated twice, yet the powder weight, for example, on my Lee at 46.4gr. is showing 47.2gr. on my digital scale?

I'm trusting the Lee one a bit more (after a decade of digi-work, I've come to dis-trust computers :)), the digi-scale did make uniformity of loads alot easier to do.
 
Well, one of'em's off, that's for sure. Do you not have any known weights (the actual term escapes me...).

Bought a set 'bout a year ago, has ½gr. through 200gr. weights for calibration and verification purposes, best scale-related accessory I've ever bought.
 
The digital scale comes with a 50 gram weight for the auto-calibration feature.


I saw some calibration weights yesterday, sigh, something else to purchase at the gun shop. :redface:
 
Use the 50gram weight to check your scales

You can also use good quality bullets for check weights.

In your case, put 4 150 gr bullets in the pan, it should read 600gr
 
If you weigh a bullet of known weight on the digital scale, does it read higher than what it should?

Get a HP bullet (not one that has a SP) like a match bullet and check the weight of the bullet on both scales. That should be a good indication of which of them is out.
 
+1 on check weights. Good to have them in several weights.

Cheap electronic scales are not always linear, or it could be the check weight is off.

You don't need extremely accurate check weights, any "school quality" weight set will do. (especially since accurate weights cost much more than most cheap electronic scales, and a fingerprint on them will throw the calibration off )

Check eBay.
 
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Calibration weights is a good thing.

Having more than one scale can be bad....:D

Now you need a third scale, so you can figure out which one is wrong. Plus some check weights.

Cheers
Trev
 
So use the 50gram weight and check them both. Seems simple enough. That is how I check my digital scale. You used it to calibrate your but did you try it on the lee?
 
Safety scale ? Does that mean balance beam? If so, it will be right unless you've somehow trashed it, in which case you'd probably notice its being sticky and/or inconsistent.
 
I just measured some of my smk's and they are band on the weight they are supposed to be. As mentioned that my be an option too.
 
I measured four, 150 grain bullets on the digital scale. Total weight: 600.8 grains.




Yes, the Lee Safety Scale is a balance beam.



I think I know what I may have been doing... I went to lock the fine adjustment of the Lee scale... And my clumsy thumb knocked the brass adjustment a tad. :eek::redface:

Why that adjustment knob isn't Loctite'd from the factory is beyond me.


Guess I'll be ultra-cautious with that last load. But based on the prior powder weighing on the Lee Scale, I know I'm good for my "old" 43.9gr. (one of the few rounds that fired :cool:), which weighed in at 44.7 (0.8gr. difference, as noted with the bullets).


Can-down said:
Here are some canadian penny weights for different years,
http://www.islandnet.com/~kpolsson/coins/canada/can1c.htm
Click to expand...

This has been added to my favourites. Nothing like a penny-pincher solution to a problem (sorry, just had to. :p)
 
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Well, according to Lee, provided the beam doesn't crack, it should be calibrated for life. Of course, I don't think he meant big clumsy fingers either. :D


Everything I was weighing was consistently short 0.8 grains on the Safety Scale. If would explain why the tabulated data for volumetric powders of the Perfect Powder measure wasn't adding up on Safety Scale, but it did on the digi-scale.
 
Cloth static or fan overhead and / or low on battery. Use same penny as a STANDERED and ten twenty loads just drop the penny in pan so you can avoid calibrating it in the middle of reloading
 
lab experience

It is not enough to calibrate any scale at one weight. Especially a weight 10x greater than what you intend to weigh. As someone said, the strain gauge response is not linear. eBay has a number of weight sets for calibration, you want one down to 1 g or less if you are weighing powder charges. Be aware that your scale probably won't calibrate at this reduced weight, most cheap scales are single-point units. What you will be doing is seeing what it says a 1 g calibration standard weighs, and using that as a correction factor on all small weights in the gram class. Typically, if you are weighing items more the 20% heavier or lighter than the calibrated weight, you cannot trust the value shown. That is to say, if you calibrate at 50 g, then you can trust it from 40 g to 60 g but not beyond.

Use a beam balance, they have fewer errors and idiosyncrasies. Get some standard gram weights so you can satisfy yourself that your weights are accurate.
 
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