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Chargemaster 1500

You must have been lucky and got a really good one. My GP250 always drifts from zero over a little time (like every 15-30 min I'll need to zero it). :mad: And that's with making sure there's no active electronics (other than the CM running on battery power) around, including no highly charged neon lighting. But, with a little patients, I manage to deal with it and get good results. :cool:
Yeah I might have got one better than some of the others out there but I’m not the only one with good luck on the GP250.

if it’s been off for a while, I’ll usually turn it on a day ahead of time before I load rounds. If I’m testing over the course of a weekend or maybe even a couple weeks sometimes, I just leave it on the whole time. It’s been on for over a week right now and I haven’t loaded any rounds since Friday but I plan to test some more later this week. Just went out and took this pic of the scale. I swear on my life I didn’t re-zero or touch anything on it before taking the pic. My radio and both CMs are plugged into the same power strip.

1B46EFCF-8446-4B1F-875A-27E6DE7DCAD6.jpeg
 
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Yeah programming helps dial in the various throw speeds but the straw or some sort of smooth insert in the drop tube is the real key to accuracy on the CM. Prevents the clumping of powder sometimes created by the drop tube threads. As you can see in the video, my CM just barely bumps the tube ahead in trickle mode and literally drops only one or two extruded kernels before stopping to re-register the weight
I had done the straw mod years ago, but had no idea on how to change the program parameters. Thanks again
 
I've been using a Chargemaster 1500 exclusively for about 3 years and I think it has significantly improved the consistency of my ammo. My biggest concern is not how it "throws", because I dump any throw that isn't exactly on target (which slows things down of course), but it is the accuracy of the scale itself and/or the rounding algorithm that is being used in the software. I have done a number of weight studies (50 throws) comparing the CM 1500 to my GemPro 500 and I pretty consistently get about 12% outside +/- 0.1gr. I've attached a Minitab graphic of the result from a study of Varget with a target weight of 24.5gr.

The obvious question is "how do I know the GemPro 500 is correct" - and the answer is, I don't. I just know they don't agree roughly 12% of the time.
 

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I've been using the RCBS ChargeMaster 1500 for over 15+ years , love it . I went down that rabbit hole and ordered a GemPro 250 a few back to double check my loads , not necessary . Even loading with IMR 4064 isn't the easiest powder to load accurately , the 1500 will do the job , great scale.
 
Steve,

You have seen my crazy reloading method and I am still using a chargemaster. Have never lost a match due to my loads, I always have better excuses for not winning anyways.
Yeah, I am now getting use to the taste of Varget.. Really would hate to stop that now... lol.. (I was using my finger not a q-tip)...
 
So, here's some numbers that represents what I experience with throws on my ChargeMaster and compared to my GemPro 250's measurement as I experimented with inserts that helped improve results from having no insert at all. I used a 1" straw that didn't improve the throws much from going without anything. A green insert is one of 3 that I bought that's designed to help with different sized orifices. And the one one that did best was a long straw that went almost all the way back leaving a small opening for the powder to feed into the tube. Results vary by powder and I always get consistent throws with AR-Comp for some reason. Because of similar size kernels, I thought Varget would throw as well as AR-Comp, but it seems Varget doesn't flow as easily (maybe something to do with the coating).

If you'll note in the picture, I've highlighted the overthrows by the ChargeMaster in grey (there were no underthrows according to the ChargeMaster), which tends to happen with the powder kernels bunch up and drop during the trickle stage. My long straw leaves a small feeding space that mitigates the bunching up by reducing the amount of powder flow down the tube. I've seen someone use a long straw set all the way back but with a slit cut into it to control the flow.


ChargeMaster throws.jpg
 
If I was able to shoot a one hole 5 shot group at 200 yards I could see being super accurate on my powder charge , I can shoot 1/2"on the average 5 even 10 shot groups at 200 yards . By fine tuning my loads didn't help much with me in the equation so 40. 4 is good enough with the CM1500..
 
Man that gem pro is not very accurate

On second thought, I think you may have not read the data there quite right??? That test was primarily to determine which orifice in the ChargeMaster's tube would produce the better results and I used the GemPro to get a fine reading. Note that there are some overthrows recorded in the ChargeMaster's column.

And since you put this question in my mind as to just how accurate my GemPro might me, having plenty of time on hand, I thought I'd run some more testing. This time, I managed to get hold of an A&D FX-120i to pit my GemPro against and proceeded to see how well my CM-1500 did (and even my little Frankford Arsenal DS-750).

This second run surprised me as my GemPro-250 showed to be as consistent as the FX-120i and almost as accurate. And it shows the CM-1500 to be as accurate as expected. Surprisingly, my little DS-750 was pretty much in line with the CM-1500.

Here's that data:
Scale Comparison.jpg

Scales.jpg
 
Nice work @Straightshooter1, thanks for sharing your work.

I see the same on my two CM1500s. I bought a second one a few years after the first one to run in tandem for days when I was staring down a whole table full of cases needing to be charged for a trip. When you go after prairie dogs or shoot several states away, you tend to suffer unless you automate as much as you can.

What I found was similar to your results, with the exception that I ran larger samples so my ES eventually grew closer to six sigma. I would toss out the over/under throws. I ran labs when I was working and had some very sophisticated Sartorius and Mettler scales to use as reference.

I summarize the CM1500 as a great tool for the money that can hold the run within an ES of 0.3 grains for batches when the operator is being careful to throw out over/under throws and is vigilant with calibration checks over longer loading sessions. Adding units makes batch loading faster so you don't find yourself waiting on the machine and you can focus on stuffing the cases with far less fatigue.
 
I see the same on my two CM1500s. I bought a second one a few years after the first one to run in tandem for days when I was staring down a whole table full of cases needing to be charged for a trip. When you go after prairie dogs or shoot several states away, you tend to suffer unless you automate as much as you can.
Yeah, if one is often doing quantities, that's the way to go.
What I found was similar to your results, with the exception that I ran larger samples so my ES eventually grew closer to six sigma. I would toss out the over/under throws. I ran labs when I was working and had some very sophisticated Sartorius and Mettler scales to use as reference.
Good to know.

Though looking a my rather small sampling, it seems the straw set up I use helps with a lower sigma. I'm using a long straw in the ChargeMaster's tube that goes all the way back leaving a small gap for the power to enter the straw (a gap of about 1/16th to 1/8th inch, depending on the kernel size). And I can still get pretty rapid throws, though I get an occasional overthrow, it's not by much (setting are: 10.00, 3.50, .050).

I summarize the CM1500 as a great tool for the money that can hold the run within an ES of 0.3 grains for batches when the operator is being careful to throw out over/under throws and is vigilant with calibration checks over longer loading sessions. Adding units makes batch loading faster so you don't find yourself waiting on the machine and you can focus on stuffing the cases with far less fatigue.
You're so right about the need to be vigilant with calibration check over long sessions. In this test, it was done over the course of a full day. I found I didn't have to do any recalibration, but did have to rezero a few times (especially on my GemPro).
 
I actually sold my FX-120i because in all my testing and checking it countless times, it was in no way better than my GemPro 250.
So now I just have the two CMs and my GemPro.

I don’t regret buying the FX120i because it was a great scale. Before having the FX, I really had nothing to verify the GP250 so I appreciated the FX for the year that I owned it because it helped me to gain complete confidence in my GP250. My GP would match the FX in accuracy at every step with everything I ever weighed. In fact, my GP was even better in many important ways. The GP is much smaller, more resistant to being slightly out of level, easier to calibrate, lifetime warranty, and almost never drifts from zero when sitting with no weight on it for long periods (days at a time). Same .02gr resolution on both scales. So I sold the FX and have no regrets.

:D Yup, you were right on. I had to prove it for myself. Now, I'm very confident with my GemPro-250. :cool:

Isn't this how science works? ;)
 
Since some people have mentioned that there's no discernable difference between what the ChargeMaster's accuracy from a more accurate scale like an FX-120i, I was curious and wondered what the number would show. Though the particular powder one is using will yield different results due to the way the powder are thrown by the CM, I used IRM-4064 and realize its large log like kernels tend to give larger variances than smaller kernel powders. But, I though it'd be interesting to see what the numbers look like.

So, the did the usual throws with the CM and weighed the throws with the FX-120i to see what the more accurate weight was. Each cartridge was numbered so that when I fired them I'd record the velocity I got that was associated with each charge weight (yes, I know there's other factors at work, but was curious at see what it looked like). I loaded 10 cartridges with the CM measured charges and 10 measured with the FX-120i.

In looking at some of my data from a little over a year ago with the CM, this test was pretty much in line with SD's and ES's I got before . . . though I must say this ES was a little higher than I typically got before. And I also tend to get a little better ES's for the more accurate scale (like my GemPro 250 that's almost as accurate as the FX-120I). What I got in terms of what I got on paper was also evident and you can see for yourself here:

CM-1500 Live Fire comparison.jpg

PS: I just notice some typo's: COAL should be 2.860 and it's .030 off the lands, not .30. :eek:
 
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I use the McDonald's straw mod to prevent clumping, and have a couple magnetic chokes on the power cord to prevent noise and static on the line from nearby noise sources as flourescents, CFMs, LED streetlights, etc. Although my power source (above ground power lines, transformer at the back corner of the yard, and lot's of radio frequency noise emitting from both) is noisy too, I still maintain a +/- .01 to .02 throw accuracy, as verified by my 250. If loading for extreme accuracy, I adjust the charge on the 250 with tweezers or a two speed trickler. It is important to level the Chargemaster, eliminate or block sources of static, make sure your power supply is clean and use the straw technique to reduce clumping, but the Chargemaster is the best I have found in 20 years of using one brand or another. Sure beats throwing with a powder measure and weighing with a beam scale, which was the first 30 years.
 
Since some people have mentioned that there's no discernable difference between what the ChargeMaster's accuracy from a more accurate scale like an FX-120i, I was curious and wondered what the number would show. Though the particular powder one is using will yield different results due to the way the powder are thrown by the CM, I used IRM-4064 and realize its large log like kernels tend to give larger variances than smaller kernel powders. But, I though it'd be interesting to see what the numbers look like.

So, the did the usual throws with the CM and weighed the throws with the FX-120i to see what the more accurate weight was.
0.2 gr throw inaccuracy is downright dismal from a CM and at least you should fit a McD's straw like

highplainsdrifter suggests. ( WTF is wrong with this bold forum text )

Anyways (WTF back to normal ?), here in NZ plastic straws that nicely fit the CM dispensing tube are not available so as is otherwise often done a bush needs be spun up to fit in the end of the dispense tube to cover the threads inside and get better drop control of the larger extruded powders.
Machining and fitting said bush was the first operation I did on my new CM after studies online before it arrived.
Also dispense programming can make a big difference apparently however I've never needed to address this although I have the info (found online) but there are some target weights that dispense speed could be improved by lengthening the medium or slow trickle time %.

The CM with a couple of tweaks is certainly fit for purpose with the extruded powders we use.

 
0.2 gr throw inaccuracy is downright dismal from a CM and at least you should fit a McD's straw like

You're right, that was "dismal". And as I mentioned, it was more than what I typically get, which is in line with the previous test I posted showing a .14 ES. But, when I saw the throw's measurement, I wasn't going to hide what had happed and left it as is. It's certainly not something I'd call a normal result. . . .but it did happen.
 

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