Scale test and question

[mikecr]

After reading the digital scale test, I'm alittle confused about the mentioned Promethious. All that Six Sigma stuff never clued me into whether it was a good powder thrower or not.
Are the Promethious produced charges generally more accurate than that produced by the RCBS Chargemaster? How fast was the Promethious in comparison? Is it automatic like the RCBS?
Thanks

 

[Forum Boss]

Bottom line, Mike, the Prometheus is accurate down very close to 1-2 kernels of powder. The Chargemaster is +/- 0.1 grain--that's about 6-7 kernels of Varget. In practice, probably 80% of the ChargeMaster charges will be within +/- 3 kernels.

The Prometheus is automatic in the sense that it throws, weighs, and dispenses the charge. As to output speed, it relies on trickling/balance beam type technology, so it should be slower than a Chargemaster, but you should really ask Brand Cole for output times with different classes of powder. Email him through www.speedweigh.com .

If you really want accuracy down to 1-2 kernels, your two choices are the Prometheus or getting a .001 gram scientific scale,$600 and up). The latter will require that you throw an under-charge first, then trickle up manually. David Tubb and other top shooters believe the ability to come within 1-2 Kernels of powder with each charge results in lower ES and better vertical consistency at long distance.

 

[mikecr]

Thank you. Thats what I needed to know.
I think I'll get one.

 

[mikecr]

Oh well their web page seems to be gone.
These people are for real, right?

 

[jb1000br]

Mike -- call Tubb -- he can give you a number for Brand

JB

 

[Longshot]

FWIW, reliable milligram scales can be had for significantly less than $600. For example, the Acculab Vicon 123 runs $320 @ www.scalesgalore.com .

I have one of these units, and it is definitely able to sense weight changes associated with a single powder kernel.

Bert

 

[jb1000br]

longshot -- good info!

Thanks,
JB

 

[bglenn]

Longshot - How long does it take for the acculab Vicon 123 scale to settle after dropping a kernel of powder on it? My Pact will take about 35 to 40 seconds to change, after adding 3 or 4 kernels, some times.
Thanks
Glenn

 

[bglenn]

UPDATE
I did some loading today in the daytime. The settling time on my pact scales was about 10 seconds, when I added 2 kernels of powder. the florescent light were not on. Could it make this much difference? Also the 0 when I returned the pan, was a little faster. Any thoughts?
Glenn

 

[Longshot]

The afore-mentioned AccuLab will display the weight change associated with a single grain of H4831SC in 2 - 7 seconds.

Finer kernel powders like Varget take maybe a skosh longer, and the response time mentioned assumes pretty stable conditions in the weighing environment.

Fluorescent lights might have an effect on the scale, especially if they're on the same curcuit as the scale. I've gotten the best results with electronic scales with them on an isolated electrical curcuit using a good line conditioner/surge suppressor.

Regards,
Bert

 

[JamesnTN]

Here are my results of using various scales.
I began reloading for accuracy many yrs ago and used the older RCBS powder dispnser and scales and depened alot on them for there reading and not knowing better. I then got serious into long range BR shooting and purchased a set of RCBS 10-10 scales.
I had found that my RCBS digital scale would read ,example) 36 grns powder and when transfered over to the 10-10 the real weight could be as much as 35.8-36.3 grns thats a +/- of .2 grns and almost .5 grn spread overall at some times it would be as much as .3-.4 grns over or under. My groups went from the 3"-4" range down to aggs of around mi 2"-high 2" groups by using the 10-10 scales for weighing my charges.
I have since gotten rid my my old dispenser and purchased the new Charge Master mainly due to the speed, and have found the accuracy to be no better than my older RCBS digital scale I also use instead of the 10-10 balance beam scale a Denver instruments lab scale that measures down to .01 grns instead of the usual .1 grn for the budget scales. I now load all my match loads with a spread difference of +/- .01 grns as this is as close as I can get to exact due to the weight of a kernal of powder. This yr I've been playing with a couple different calibers in the 600 yd matches and not ben up on my game with what I'm capable of shooting and also experiminting with a new rear bag for my LG. The last match I went back to my 22 Dasher and was playing with a couple rear bags to see what the rifle liked best and shot best at and by the second half of the match I figured it out and got the 22 dasher shooting back down in the low 2" and high 1" range at 600 yds.
If you want accuracy don't depend on budget scales either purchase a good Balance beam scale such as the RCBS 10-10 or get a high end lab grade scale and a certified check weight to calibrate them with.
Hopefully I have all my ducks in a row for the July match and am done experiminting to try and break my own group record and get below the 1" barrier and do some real shooting once again.

Good luck in your quest for accuracy and if any of you are in the market for balance beam scales I have a few used ones in stock that all check out good.

James Phillips
Reloaders Nest