Measuring The Chargemaster Scale Accuracy

4Rail_Gunner

4Rail_Gunner

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Minuteman
Jul 3, 2006
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Stephenville, Texas
#1
I recently bought an Acculab VIC-123 and thought I would measure what MY chargemaster puts out and determine its true accuracy.

I use the chargemaster in conjunction with the Acculab so I set up the chargemaster to the exact .1 grain of powder I wanted and let it run and wrote down what came out.
If it was over or under then I didn't write down that charge. I only wrote down what was supposed to be exactly the charge I wanted.

Now I measure with the pan so its whatever charge plus the weight of the pan which is 172.72 Grains.

Here is the numerical figures
H4350
43.7Gr + 172.72 = 216.42Gr Target
1st 216.38gr
2nd 216.34gr
3rd 216.46gr
4th 216.46gr
5th 216.38gr

H4350
44.0Gr + 172.72 = 216.72Gr Target
1st 216.88gr
2nd 216.72gr
3rd 216.78gr
4th 216.74gr
5th 216.78gr

H4350
44.3Gr + 172.72Gr = 217.02 Target
1st 217.02gr
2nd 217.18gr
3rd 217.08gr
4th 217.12gr
5th 217.14gr

H4350
43.0Gr + 172.72Gr = 215.72gr Target
215.72gr
215.72gr
215.80gr
215.72gr
215.66gr
215.66gr
215.70gr
215.78gr
215.76gr
215.74gr

Just some food for thought.

Thanks
 
#2
Re: Measuring The Chargemaster Scale Accuracy

Thanks for sharing.

Did you leave your chargemaster under tension ? (to avoid erratic measurements at the beginning of the process)

Did you try another type of powder to see if the "bean" structure have some influence on scaling/dispenser ?
 
#3
Re: Measuring The Chargemaster Scale Accuracy

I just let everything warm up properly before I started calibrated and let it set with the pan on it zeroed.


I did measure 20 rounds of Varget, but didn't take notes when I did it.
It does seem like some of the H4350 powder charges are easier to get almost perfect than others.
 
#4
Re: Measuring The Chargemaster Scale Accuracy

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 4Rail_Gunner</div><div class="ubbcode-body">I recently bought an Acculab VIC-123 and thought I would measure what MY chargemaster puts out and determine its true accuracy.

I use the chargemaster in conjunction with the Acculab so I set up the chargemaster to the exact .1 grain of powder I wanted and let it run and wrote down what came out.
If it was over or under then I didn't write down that charge. I only wrote down what was supposed to be exactly the charge I wanted.

Now I measure with the pan so its whatever charge plus the weight of the pan which is 172.72 Grains.

Here is the numerical figures
H4350
43.7Gr + 172.72 = 216.42Gr Target
1st 216.38gr
2nd 216.34gr
3rd 216.46gr
4th 216.46gr
5th 216.38gr

H4350
44.0Gr + 172.72 = 216.72Gr Target
1st 216.88gr
2nd 216.72gr
3rd 216.78gr
4th 216.74gr
5th 216.78gr

H4350
44.3Gr + 172.72Gr = 217.02 Target
1st 217.02gr
2nd 217.18gr
3rd 217.08gr
4th 217.12gr
5th 217.14gr

H4350
43.0Gr + 172.72Gr = 215.72gr Target
215.72gr
215.72gr
215.80gr
215.72gr
215.66gr
215.66gr
215.70gr
215.78gr
215.76gr
215.74gr

Just some food for thought.

Thanks </div></div>

I think that it's pretty much SOP across the board, that this type of scale has an accuracy tolerance of +/- .1 grain, so it appears to be well within spec. Thanks, I can now sleep better at night!

No doubt the Denver Instruments/Acculab VIC-123 is a more accurate scale with a finer resolution.

Life's too short to be counting kernels!

Chris
 
#5
Re: Measuring The Chargemaster Scale Accuracy

Good info for sure.

I've often wondered how accurate my RCBS scale is. I calibrate before each session and check the calibration with the weights every so often during a session and it's never off.

However, it's only .1gr accurate so I know there is some variance in there. Sometimes going back and spot checking previously thrown charges shows them off by +.1gr. It never comes back lighter than previously measured.
 
#6
Re: Measuring The Chargemaster Scale Accuracy

If the load you are using isnt at least .2g stable (IE +/- .2G) then you need to find another load. The CM1500 is more than enough for me IMHO.
 
#7
Re: Measuring The Chargemaster Scale Accuracy

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: USMCj</div><div class="ubbcode-body">If the load you are using isnt at least .2g stable (IE +/- .2G) then you need to find another load. The CM1500 is more than enough for me IMHO. </div></div>

My loads are within .1 stable. Sometimes it's off by .1 but never by .2.
 
#8
Re: Measuring The Chargemaster Scale Accuracy

Extreme spreads of { 0.12, 0.16, 0.24 }gr.

Not bad. I guess one could argue that it is within 0.1 gr SD; however, it is not within 0.1 gr ES. Inside 600 yards, or so, you will never see the difference.
 
#9
Re: Measuring The Chargemaster Scale Accuracy

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Jayne</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: USMCj</div><div class="ubbcode-body">If the load you are using isnt at least .2g stable (IE +/- .2G) then you need to find another load. The CM1500 is more than enough for me IMHO. </div></div>

My loads are within .1 stable. Sometimes it's off by .1 but never by .2. </div></div>

I'm just throwing this out, but I think USMCj is referring to the SD for real world loads that are +/- .2 grains off the target weight. He is of the opinion that for 'good' loads, being off by that amount, either up or down, should NOT matter on paper

While we all strive to have everything identical in our ammo loading, the SD variance in velocity for some of these things: flash hole deburring, case length, bullet weights and specific to this conversation, charge weight is really quite negligible once things get chronoed.

Maybe out past a thousand yards, one might get some verticle stringing, but not at shorter distances. At least with a human being shooting. Maybe with a ransom rest, things would be different?

With all the other variables in play, six kernels up, or down, most likely won't show up anywhere. To this end, the Chargemaster type scales are more than sufficient with their accuracy of +/- .1 grains.

Chris
 
#10
Re: Measuring The Chargemaster Scale Accuracy

Brandon
As you mention the acculab reads to .02 so using this being off .1 is 5 times the scales accuracy
the acculab will make you anal rtetentive like me to load within .04 gr
Bill
 
#11
Re: Measuring The Chargemaster Scale Accuracy

Often times people worry more about the little things. I use the Chargemaster and works great. I don't think there is a better powder dispenser for the money.

If you are trying to set the world record. I would spend hours on loads ( turn necks, measure and weigh brass +bullets etc.) But for shooting steel and paper. The charge weight of the powder +-.01 grs will not make a difference at 600 yards. I think at 1000 and beyond it will if shooting for groups.

Try this work your completely (brass, neck turn , powder down to the kernel). Shoot the loads at 600 yards and see if it would be worth the extra or not.



 
#12
Re: Measuring The Chargemaster Scale Accuracy

Bought this scale to lower my ES and SD numbers. Taking one less variable out in my 260 loads. Currently doing load developement on a new lot of powder as it has slowed down from my previous lot.
Chrono'd loads produced by the Chargemaster had ES of 37.05 and SD of 14.86
Chrono'd loads produced with Acculab are down to ES of 25.51 and SD of 9.59
The local range is either 100 to 500 or 1000. So I usually mess around at 1000. If the Acculab will take out some of the WTF high or low misses then it's worth it to me.
Still not satisfied with my ES numbers I changed primers and it has went down to an ES of 17 and SD of 7.41
Extreme spread isn't everything in shooting, but it is something to work at lowering.
 
#13
Re: Measuring The Chargemaster Scale Accuracy

I use the chargemaster. I can get SDs around 5 to 9 on the SDs. I do have to play with seating depths and charge weights. I have loaded for the 260 a lot. So I have a great starting point.

When I chrono a load. I use a 20 shot group to give me the SDs. Often times on some loads I will shot a 3 shots over the chrono and the SDs will be like 5 but shooting 20 shot over. They will average around 8. I usually settle around the 8 range on the SDs or better. The chargemaster has work great for me to achieve these results.
 
#14
Re: Measuring The Chargemaster Scale Accuracy

I think your right on track. I have used the acculab for all load testing and measuring to the Kernel of powder.
I look at this the same way you do removal of a variable.
its a great scale and only as fast as you are. but accurate as all get out!!!!!!!!!

Bill

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 4Rail_Gunner</div><div class="ubbcode-body">Bought this scale to lower my ES and SD numbers. Taking one less variable out in my 260 loads. Currently doing load developement on a new lot of powder as it has slowed down from my previous lot.
Chrono'd loads produced by the Chargemaster had ES of 37.05 and SD of 14.86
Chrono'd loads produced with Acculab are down to ES of 25.51 and SD of 9.59
The local range is either 100 to 500 or 1000. So I usually mess around at 1000. If the Acculab will take out some of the WTF high or low misses then it's worth it to me.
Still not satisfied with my ES numbers I changed primers and it has went down to an ES of 17 and SD of 7.41
Extreme spread isn't everything in shooting, but it is something to work at lowering.


</div></div>
 
#15
Re: Measuring The Chargemaster Scale Accuracy

Be sure to let the scale warm up mine can vary for the first hour or two and now I just leave it on .
second you can rezero once the pan is on measuring the load only?
Bill

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 4Rail_Gunner</div><div class="ubbcode-body">I recently bought an Acculab VIC-123 and thought I would measure what MY chargemaster puts out and determine its true accuracy.

I use the chargemaster in conjunction with the Acculab so I set up the chargemaster to the exact .1 grain of powder I wanted and let it run and wrote down what came out.
If it was over or under then I didn't write down that charge. I only wrote down what was supposed to be exactly the charge I wanted.

Now I measure with the pan so its whatever charge plus the weight of the pan which is 172.72 Grains.

Here is the numerical figures
H4350
43.7Gr + 172.72 = 216.42Gr Target
1st 216.38gr
2nd 216.34gr
3rd 216.46gr
4th 216.46gr
5th 216.38gr

H4350
44.0Gr + 172.72 = 216.72Gr Target
1st 216.88gr
2nd 216.72gr
3rd 216.78gr
4th 216.74gr
5th 216.78gr

H4350
44.3Gr + 172.72Gr = 217.02 Target
1st 217.02gr
2nd 217.18gr
3rd 217.08gr
4th 217.12gr
5th 217.14gr

H4350
43.0Gr + 172.72Gr = 215.72gr Target
215.72gr
215.72gr
215.80gr
215.72gr
215.66gr
215.66gr
215.70gr
215.78gr
215.76gr
215.74gr

Just some food for thought.

Thanks </div></div>
 
#16
Re: Measuring The Chargemaster Scale Accuracy

Be sure to let the scale warm up mine can vary for the first hour or two and now I just leave it on .
second you can rezero once the pan is on measuring the load only?
Bill
I could zero with the pan on the Acculab, but i take the loaded pan off my Chargemaster and set it on the Acculab. So I just want to make sure the scale is at 0.00 before I set the pan on instead of -172.72 (if it was zeroed with the pan)

And I've too just leave it on now unless I'm not doing any reloading for the week.
Click to expand...
Click to expand...
 
#17
Re: Measuring The Chargemaster Scale Accuracy

think of how much better this is than the balance scale. I always wondered how accurate the varget pours out of it though?

Anyone with a seperate digi care to weight a few?

thanks
 
#18
Re: Measuring The Chargemaster Scale Accuracy

I did load some Varget onto the Acculab but didn't write down the measurement results. It metered the same as H4350 to me.
Some hunting loads I chrono'd showed ES 18.57 and SD of 5.74 over 5 shots.
 
#20
Re: Measuring The Chargemaster Scale Accuracy

I haven't reprogrammed my chargemaster. I've read the post on how to do it, just never have messed with it.
To make loading faster I am going to pickup 2 Identical powder pans, work over and get them to the exact same weight. Then have on pan on the Chargemaster with it running while I'm messing with the Acculab getting the charge perfect.
 
#21
Re: Measuring The Chargemaster Scale Accuracy

I'm curious if your CM has the "straw trick" installed? Would this bring the numbers in even more (though I'm fine with .1)?

The straw prevents a larger dump of several kernels as the scale gets close and is on very fine trickle.
 
#22
Re: Measuring The Chargemaster Scale Accuracy

as far as getting two pans to the same exact weight. i used the plastic lyman pan and glued a nickel to the bottom of it so the scale would read it. FYI
 
#23
Re: Measuring The Chargemaster Scale Accuracy

ChargemasterStaw.jpg

I tried the straw trick, all it did was spill powder everywhere.
lol
On a serious note, I did install a 1/2inch of a wendys straw in the powder tube before I ever got the Acculab.
 
#24
Re: Measuring The Chargemaster Scale Accuracy

The straw didnt do the trick on mine, it was too slick causing kernels to drop after it stopped spinning. Instead I rolled up a piece of printer paper to twice the thickness of a straw, and I reprogrammed my CM1500 to work faster. In the last 3 months, I have not had a single trow over or under the target weight. And I my CM has not been powered down in over a year.
 
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