Digital scale questions

[eddywitay]

I need a little guidance on selecting a good scale I was thinking of the Sartorius ay123. I see that It gets good reviews and some bad reviews. I really don't want to spend the money for a Sartorius GD503.With the drifting problems that I see people having how much Is to much I am currently using a RCBS range master 750.even with the drift of the Sartorius It still has to be way better than my RCBS range master right????? Any advice would be great because I don't know what to do..

THANKS

 

[Keith Glasscock]

I definately do not recommend the GEMPRO! Mine had to go back after the first day.

As for being better than the RCBS, it depends.

I ran my old RCBS 90 (made by Ohaus) against my new GEMPRO 250 and found something I didn't know. I can throw 30 charges with an ES of .04 grains repeatedly! That's +/- one kernel of Varget.

Since most large-kernel powders run about .02 grains per kernel, the best you are going to do is +/- .01 grains with a perfectly accurate half-milligram scale. With my demonstrated ES, I'm +/- .02 grains (perhaps .03 because the resolution of the GEMPRO is .02 grains).

Do I have a super-scale? Maybe, I don't know...

Here is what I would suggest:

If you have a friend that has a milligram or better scale, put together 10 charges to the best of your ability and secure them in small, sealed containers. Take them over to your friend's place and have him (or her) weigh your charges and see what you have. If it is +/- .10 grains, by all means, you might see a strong benefit from a lab balance. If it is .04, I think your money could be better spent.

Here is a big question: How much change in velocity do you get from a 1 grain change in powder charge? In my case, it is 50 fps. That means that an ES of 0.1 grains would cause a velocity difference of 5 fps. With the demonstrated performance of my scale and technique, I'm getting ~ 2 fps. If I were to cut it to +/- .01, it would be, say 1 fps?

This is all just my opinion and could very well be worth exactly what was paid for it...

 

[BlackEagle]

BUSDRIVER- what problems did you have with your GEMPRO? I have had one a couple months and I've only used it 3 different sessions. Each loading session I had it drift away from zero by about 0.02 - 0.04 grains a couple times and had to rezero it. It is not a huge problem but I am dispappointed and I've been thinking about sending it in. How was the service when you sent yours back?

 

[rogn]

I got a Dillon a couple of years back just to use to weigh in lots of brass or cast bullets. Now its all I use, except to check weights with the Ohaus balance- to double check and to reference. I leave the balance set at the established weight to have a reference setting( when you get to a certain age you can forget where yer going even on the way to the bathroom). It you want the peak accuracy and repeatability you always approach your final weight from the same direction, I always arrive at the final weight on the way up. This seems far better than coming down to the weight. This allows you to really find the one grain of powder that trips the last 0.1 gr and is very repeatable. Mine is kept plugged in with a surge suppressor, and is left on most of the time. This avoids warmup and other issues. Drift is minimal and very predictable- easily detected by not returng to zero when pan is replaced. And if I detect drift I just rezero and move on. This happens occasionally if I move too soon on warmup, but rarely otherwise. Cost was moderate and its not given me any misgivings since I got it.

 

[Keith Glasscock]

I sent mine back to the vendor after a single test session.

Mine wouldn't calibrate well. It would show 19.997 grams after calibration. Regardless of what I did, it didn't calibrate. When I tested the consistency with the provided check weight, I got some really funny results over a rather short period of time (+.002 grams to -.003) It did, however, weigh lighter charges consistently. From my check weights, I was able to determine that it was able to give me a consistent, albeit wrong, reading (off by .06 grains or so). That is why I was able to determine weight spread, but not actual weight. I also found it necessary to re-zero the scale after every 2-3 weighings. There was something wrong there...

As for my experience with warranty, the vendor took the scale back because it wouldn't calibrate from the get-go and had an AC adapter problem (one prong came out). I got my money back, and am VERY HAPPY with Old Will Knott!

If mine only needed rezeroing every 5 loads or so, I'd just live with it. That doesn't seem bad at all. I actually do rezero my scales frequently during a reloading session. The RCBS has a zero-holding function where it rezeros automatically if the reading is zero for more than a few seconds.

You can test to see if your scale has one by doing the following:

Warm up the scale
Zero the scale with a powder pan on it
Weigh a charge or bullet
Replace empty pan and verify that the scale reads zero
Wait 20 seconds
Drop 1 kernel of powder in the pan
Wait 20 seconds
Drop 1 more kernel
Repeat the drop then wait until you have 5-10 kernels in the pan

If the scale stayed at 0.0 the entire time, remove the pan and pour out the powder
Replace the pan and see if the scale reads a negative number (-0.1 to -0.2)

If it does, your scale has a zero holding feature. I take advantage of this feature by replacing the pan on the scale between charges (I powder and seat bullets in one operation)

rogn,
Your technique is what I'm using. It works great! I use the spot where the reading is jumping back and forth between two readings. I can double check a charge if I have to that way.