My test - Chargemaster vs. Sartorius

[GardDog]

I picked up a Sartorius AY-123 scale a few months back, with the intent of using it to increase the effectiveness of my hand loads. I'll never get a Prometheus, so this (for me) is the next level of accuracy in thrown charges. I attempted to use the scale right after buying it, but I never could get a repeatable zero. I learned that I had not given the scale a proper warmup cycle, so my impatience was affecting the trial.

Today, I set out to test charges thrown by my Chargemaster and see if I could get one kernel accuracy out of the Sartorius. I had 49 (#50 was lost on the mile tower at NTRP, never to be found) pieces of once fired Winchester .300 wsm brass prepped. I ran 49 charges of 67.2 gr of R-19 on my RCBS Chargemaster. I then took 25 and reweighed the charge on the Sartorius. The results were as follows:

I then took the 25 and got them to 67.20 gr, down to the kernel. I left the other 24 as they were thrown, to use as my standard. Next week, I'll shoot the 49 over my chronograph and check accuracy and performance at 100, 300, 500 & beyond.

I'm already getting .4 moa accuracy with the CM thrown loads, so I'm looking forward to seeing if I shoot well enough to notice a difference in the Sartorius loads. I'm getting the hang of the new scale and I will see if it's worth the extra effort.

More to come.

 

[Dave-O]

Re: My test - Chargemaster vs. Sartorius

Welcome to OCD.

I did basically the same test when I setup my sartorius, it proved to me that my chargemaster did in fact throw within the .1gr that it claims.

I paired an omega trickler with it to get down to 1 kernel accuracy..

Where I noticed the biggest difference is at distance, loading better ammo cut down my vertical dispersion a fair amount. Now, if I could cut down the shooter induced dispersion, I'd be all set.

Enjoy your new scale. It's a great tool

 

[GardDog]

Re: My test - Chargemaster vs. Sartorius

It helped that I was using R-19, because it consists of different sized kernels. If I had to pick out H414, I'd have given up! Oh yeah, the OCD reloading sickness is strong! I'm hoping that this will help in my quest for a mile. I know that I'll never notice a difference at short range.

 

[Mike Sobr]

Re: My test - Chargemaster vs. Sartorius

Were you using the straw mod on the CM?

 

[IanB]

Re: My test - Chargemaster vs. Sartorius

I have done the same test but using a Gempro 250. I have to say I'm impressed with the accuracy of the RCBS chargemaster.
Out of 50 charges I had two rogue charges thrown (using a straw)the Gempro weeded these out, the rest I trickled up using the excellent Omega, anything that was .02 of my desired charge I left as it was.
I shoot F class so consistancy is vital for long range accuracy. When I get vertical now at extended ranges I'm now confident enough to say its the conditions and not my ammo.

 

[OneShotJim]

Re: My test - Chargemaster vs. Sartorius

Looks like a great test you have set up GardDog. Looking forward to your chrono & accuracy results. This kind of info on how well different scales & power measures work is very valuable. Thanks in advance!

 

[turbo54]

Re: My test - Chargemaster vs. Sartorius

Wow, those results are surprising, in particular the .48gr deviation sample...

Statsistics tells us that once you've got sufficient samples, you can add 3 standard deviations to your mean, subtract 3 SD's, and have 99.7% confidence that every sample you'll ever see will fall within that window.

Therefore:

Your mean was 67.2
Your SD was .12

3 times your SD is .36

mean + 3*SD is 67.56
mean - 3*SD is 66.84

So, there is a 99.7 chance your chargemaster will ALWAYS be between 67.56 and 66.84gr... Which isn't terribly impressive. I did a similar study with my RCBS uniflow with Varget and got very similar standard deviation. If your results are correct, that indicates the CM1500 is of no benefit over a uniflow powder measure.

 

[milo 2.0]

Re: My test - Chargemaster vs. Sartorius

GarDog,
Thanks for the info, I trust my chargemaster to deliver within my shooting capabilities. You've just confirmed it.

 

[clmayfield]

Re: My test - Chargemaster vs. Sartorius

I did a test a while ago comparing the Acculab VIC-123 (the old version of the Sartorius AY-123) to the Chargemaster using my GD-503:
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">
This post caused me to do an experiment. I decided to test my Chargemaster against my VIC-123 against my GD-503. Could it be that my Chargemaster is within a kernel like a Prometheus and I just didn't know it?

I wish I could figure out how to publish my spreadsheet. I calibrated all 3 per instructions, threw a 43.0 gr charge with Varget on my Chargemaster, and weighed on my Acculab VIC-123 and then on my Sartorius GD-503. I weighed the Chargemaster pan on both scales because I need to rezero my VIC-123 before weighing, and this allows me to calculate sample weight. My VIC showed the pan weight to be 142.40 gr while my GD-503 showed the pan weight to be 142.420 gr.

I threw 30 times (actually 31, but one was an overthrow, so I dumped it and redispensed).

What I found was that the standard deviation of the Chargemaster was 0.0415 grains. Multiplying the SD by 2 gives me where I am confident I will be 95% of the time (actually, where my average will be, but no need to get into that). Basically, the Chargemaster is +/- .083 grains. Not bad... that is better than the .1 gr precision that the CM reads to. This translates to +/- roughly 4 kernels of Varget with the CM. That is half of what I was quoting earlier.

The largest mistake was an overthrow of .0922 grains, which happened twice. The largest underthrow was a .0828 grain underthrow. To get the terminology right, I only weighed samples where the CM read 43.0, so the CM was not reading it as an overthrow or an underthrow, it just was an overthrow or an underthrow according to my target weight.

I think the CM performed pretty well. Similarly, the VIC-123 performed pretty well. 8 of the 30 times it varied by about .02 grains, or roughly a kernel. It never varied by more than .025 grains, so it was never as many as 2 kernels off.

I also retested my theory about the weight of a kernel of Varget. I calculated 3 ways... first by weighing a single kernel on the GD-503, then by weighing 5 kernels together and dividing by 5, and finally by weighing 20 kernels.

With wieghing a single kernel, my scale read either .02 gr or .015 gr. The average I came up with was 0.019 grains, but I decided that wasn't a realistic number for the resolution of my scale, so I weighed multiple kernels. Weighing 5 kernels at a time 6 times, I came up with an average weight of .0203 grains. Weighing 20 at a time, I came up with a .022 grain average per kernel. In other words, there is some variation from kernel to kernel, including weights below .02 grains per kernel, but on average, a kernel weighs about .021 grains or so.

Interesting stuff. I learned a little bit. I hope everyone else learned something as well.
</div></div>

So the AY-123 will get you to a +/- kernel. I much prefer the GD-503, however, because it works better for trickling onto the scale. You see, the AY-123 uses a strain gauge and to make that strain gauge work, it needs an algorithm to try to increase stability. I haven't read this anywhere, but my theory is that with the addition of small amounts of weight, the algorithm will try to stabilize the reading, causing it to drift when trickling a kernel at a time.

In order to get a sound reading, you really have to trickle up to the charge, pull the charge off, rezero, and then reweigh to get true +/- a kernel accuracy.

With the GD-503, you trickle up and whatever the scale reads when it shows stable is the number. You never have to rezero during a session. I calibrate every time anyway, but it is not really necessary.

 

[milo 2.0]

Re: My test - Chargemaster vs. Sartorius

Can you guys really shoot between these numbers?
Wind is my biggest enemy. I notice most of you aren't in the F-Class thread.

 

[Tpb10505]

Re: My test - Chargemaster vs. Sartorius

tag

 

[Gene Poole]

Re: My test - Chargemaster vs. Sartorius

You beat me to it Carter. I was going to post some similar results, but I didn't have any hard data; just the anal-retentive chemist in me triple checking everything.

I've tested a few throws from the CM on our Ohaus DV215CD at work (on its granite pedestal in a temperature controlled lab with our NIST calibrated weights) and I don't get near the spread as the OP. The Ohaus showed that the CM was accurately dispensing throws that were well within its 0.1 grain range (i.e. a 44.0 grain throw on the CM was between 43.95 and 44.04) on all charges that actually read 44.0 on the CM.

 

[clmayfield]

Re: My test - Chargemaster vs. Sartorius

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: milo-2</div><div class="ubbcode-body">Can you guys really shoot between these numbers?
Wind is my biggest enemy. I notice most of you aren't in the F-Class thread.</div></div>

You know, it is interesting. I never thought the 1 kernel would make a big deal. I went and loaded up a bunch of rounds for short range using the CM and my average group size went way up at 100 yards. Now that is just one session... but the only thing worse than spending a bunch of time in the reloading room is spending a range trip missing what you are aiming at.

 

[QuiggyB]

Re: My test - Chargemaster vs. Sartorius

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Gene Poole</div><div class="ubbcode-body">You beat me to it Carter. I was going to post some similar results, but I didn't have any hard data; just the anal-retentive chemist in me triple checking everything.

I've tested a few throws from the CM on our Ohaus DV215CD at work (on its granite pedestal in a temperature controlled lab with our NIST calibrated weights) and I don't get near the spread as the OP. The Ohaus showed that the CM was accurately dispensing throws that were well within its 0.1 grain range (i.e. a 44.0 grain throw on the CM was between 43.95 and 44.04) on all charges that actually read 44.0 on the CM. </div></div>

My problem with the CM was that the zero would drift over time. That .05gr variance would turn into .3 grains.

I just went to dropping a close charge with a regular powder thrower, weighing on a GemPro 250 which goes down to .02 and is easy to keep a good zero on, and trickling up with an omega. Its a lot faster than the CM to boot and my range is +/- .02. GemPro costs ~$160. Id like a GD503 but its hard to justify if you arent loading ammo for profit.

The Sart AY123s and their clones are pretty bad about having inconsistent zeros.

 

[taseal]

Re: My test - Chargemaster vs. Sartorius

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Carter Mayfield</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: milo-2</div><div class="ubbcode-body">Can you guys really shoot between these numbers?
Wind is my biggest enemy. I notice most of you aren't in the F-Class thread.</div></div>

You know, it is interesting. I never thought the 1 kernel would make a big deal. I went and loaded up a bunch of rounds for short range using the CM and my average group size went way up at 100 yards. Now that is just one session... but the only thing worse than spending a bunch of time in the reloading room is spending a range trip missing what you are aiming at. </div></div>

don't blame missing your target at a single kernel of powder now!

 

[QuiggyB]

Re: My test - Chargemaster vs. Sartorius

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: milo-2</div><div class="ubbcode-body">Can you guys really shoot between these numbers?
Wind is my biggest enemy. I notice most of you aren't in the F-Class thread. </div></div>

One of the most important things I have found with 1000 yard fclass is keeping consistent vertical. Doing that lets you consistently put the shot in the center of the target elevation wise which gives you the maximum amount of room for error on windage. The X ring is 10 inches across its center. If you have a vertical error of 1/2 moa your X shot becomes a 9.

 

[Grump]

Re: My test - Chargemaster vs. Sartorius

This reply below assumes that the CM charge distribution will be "normal."

With sensing and process controls at play, I'm not sure distribution *would* be normal. Having weighed 50 or more charges in a row from various volumetric powder measures, I'll leave it to others to record 100 ChargeMaster throws to see whether it approaches normal.

Later,

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: turbo54</div><div class="ubbcode-body">Wow, those results are surprising, in particular the .48gr deviation sample...

Statsistics tells us that once you've got sufficient samples, you can add 3 standard deviations to your mean, subtract 3 SD's, and have 99.7% confidence that every sample you'll ever see will fall within that window.

Therefore:

Your mean was 67.2
Your SD was .12

3 times your SD is .36

mean + 3*SD is 67.56
mean - 3*SD is 66.84

So, there is a 99.7 chance your chargemaster will ALWAYS be between 67.56 and 66.84gr... Which isn't terribly impressive. I did a similar study with my RCBS uniflow with Varget and got very similar standard deviation. If your results are correct, that indicates the CM1500 is of no benefit over a uniflow powder measure. </div></div>

 

[clmayfield]

Re: My test - Chargemaster vs. Sartorius

I have the numbers for 30 throws... all that is needed for a single average... and to my recollection, distribution looked pretty normal. For weights and measures, that is very typically the case.

 

[clmayfield]

Re: My test - Chargemaster vs. Sartorius

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: taseal</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Carter Mayfield</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: milo-2</div><div class="ubbcode-body">Can you guys really shoot between these numbers?
Wind is my biggest enemy. I notice most of you aren't in the F-Class thread.</div></div>

You know, it is interesting. I never thought the 1 kernel would make a big deal. I went and loaded up a bunch of rounds for short range using the CM and my average group size went way up at 100 yards. Now that is just one session... but the only thing worse than spending a bunch of time in the reloading room is spending a range trip missing what you are aiming at. </div></div>

don't blame missing your target at a single kernel of powder now!

</div></div>

Like I said... I didn't expect that result, but I am not talking one kernel. The CM is off +/- .08 grains. It could have been a lot of things. I only tried it once. And I have had many days when I changed nothing and shot like crap, so I wouldn't consider my results based on one outing without a control scientific.

 

[GardDog]

Re: My test - Chargemaster vs. Sartorius

Sorry for the delayed posting of results. I was just able to head out to the cane field proving grounds yesterday.

For purposes of uniformity, I shot the loads over a Shooting Chrony Beta Master at 15 feet. The case prep and loading methods were identical for all groups. I labeled the rounds loaded by verifying the charge with the Sartorius as Group #1 and the rounds loaded by just utilizing the RCBS Chargemaster as Group #2. I shot 5 rounds from Group #1 and then 5 rounds from Group #2 and the repeated the process for a total of 10 rounds from each Group over the chronograph. Some will question the limited data from just shooting 10 of each. I understand that, as to be more scientific, you need a larger group from which to gather data. My answer is that the components aren't exactly cheap and I'm not going to run 200 rounds just to satisfy the math gurus. I alternated 5 shot groups to indicate any inconsistencies with my chronograph (I sometimes see an odd increase in MV towards the end of a string of fire). To throw in another feature, I ran 10 rounds of the same load, but in Federal brass to check the variation of using different cases.

My results:

Group 1 (RCBS verified by Sartorius)

Group 2 (RCBS Chargemaster)

Group 3 (Same load with Federal brass)

I then put 5 rounds from each group on steel and 5 rounds from each group on paper. Group 1 was .2 moa tighter on steel and .3 moa tighter on paper at 300 yards.

To be honest, overall I shot like crap yesterday. I can blame it on the mirage, the ex-wife's voodoo doll or planetary pull... the bottom line is that I've shot this load alot better than I did yesterday, so I'm not ready to throw it in the garbage. The only good thing was that I was consistently bad for all of the loads.

What I learned:

The Federal brass cannot be interchanged with Win brass, without affecting dope.

The loads verified by the Sartorius only averaged 1 fps different. Sounds like there is no need to go the extra mile and twease kernels of powder... Right? Well, when I see an improvement in ES of 24 fps and SD of 9, I am now more likely to learn towards the extra step. I also had a better average velocity to base my dope off of. My previous average velocity (gained from initial load testing) was 28 fps faster, thus affecting my 1000 yard dope by .2 mil and 1 mile dope by .5 mil.

My goal with this rifle / load is one mile. The difference in performance will really pay off at that range. Also, I worked the extra step into my process (instead of weighing and recheckeing at the end) and it doesn't add that much into my time invested.

 

[jhelmuth]

Re: My test - Chargemaster vs. Sartorius

I know I'm coming late tothe party, but this was an EXCELLENT reinfocement for my own loading practices. I too have a GemPro 250 which I am using against the CM1500. I'm experiencing the same things as noted here and in other post on such topic.
You saved me the time and effort toward the verification I was looking for.

Thank you!

 

[PRKmachinist]

Re: My test - Chargemaster vs. Sartorius

Excellent info - I was planning on doing this testing myself.

 

[vman]

Re: My test - Chargemaster vs. Sartorius

Great post, thank you