RCBS Chargemaster 1500 - How Accurate?

[Jager]

​

For a bunch of years now I have said that two things were game changers in my shooting world… the introduction of an accurate, reliable digital scale; and the accessibility of precise, easy-to-use chronographs.

Both of those, together, fundamentally changed how I approached handloading.

I’d now add a third – QuickLoad software. But that’s a story for another day.

Like many here, I began loading ammo a long, long time ago. And for most of us, that meant uncounted hours in front of an analog beam scale. That 10-10 scale of mine saw yeoman service across literal decades, and never gave a lick of trouble in all that time. When I open the door to my powder closet and see it resting there on the shelf, I cannot help but smile.

But I haven’t actually used it in years. The day my Chargemaster 1500 showed up was revelatory. And after using it for only a couple of loading sessions I knew I would never be going back.

For all its benefits of speed and convenience, though, the Chargemaster didn’t bring any improvement in precision – it came claiming the same 0.1 grain accuracy that its numerous analog predecessors had long offered. It would be many more years before affordable technology would grant us the ability to look back and see what we had.

Nowadays, my scale of choice is an A&D FX-120i. That’s not the only good scale out there, of course. There are even better, pricier models available – the esteemed Sartorius comes to mind. But the FX-120i strikes a good balance between price and performance. And it’s popular among many serious handloaders (I say “serious” not as a slight to anyone who doesn’t choose it, but rather simply as a nod to its price point… I don’t know of anyone who would pay the coin for one if they weren’t pretty serious about their handloading).

More particularly, one of the benefits of a laboratory-grade electromagnetic force restoration scale like the A&D or the Sartorius is that it allows you to evaluate their older strain-gauge (or analog) brethren. The much deeper levels of precision a lab balance offers – 0.02 grain in the FX-120i or 0.01 grain in the Sartorius – allow us to, finally, judge the efficacy of those older scales.

With that in mind, I decided to throw a few charges with the Chargemaster, weigh them on the A&D, and see what I got. It’s an interesting experiment… the Chargemaster, after throwing its charge, sits there with a number painted on its LCD screen. That number seems solid, resolute, unequivocal. You very much have the feeling that that number is the number.

And then you lift the pan and carefully place it on the A&D…





The Chargemaster actually acquits itself pretty well. Of 26 charges thrown, only one – the 10.72 gr charge in the third group – was outside its 0.1 grain spec, and that just barely. The average throws are very close to the target weight. And the standard deviation isn’t bad.

How about with a cartridge of higher capacity, using an extruded powder?





Again, the Chargemaster does a pretty good job. Out of 20 charges thrown, only one – the 34.12 gr in the last group – is slightly out of spec.

I think it’s mostly a good-news story. The Chargemaster seems to reliably live up to its promises. I still use mine occasionally. Especially with larger capacity cartridges where a charge variation of some hundredths of a grain isn’t going to make much difference; or with loads where less precision is required.


One last twist, though… those of us who use QuickLoad know that you can (and should) tweak the Burning Rate factor in that software to dial in the particular powder lot you’re using. What I’ll do as I run near the end of a current lot of powder is build a handful of rounds of a known load, using known primer and brass, using the old powder; then load an equivalent number of rounds using the new lot of powder. Setting off those two groups in front of a chronograph will then give me a quick first baseline of where the new powder sits vis-à-vis the old lot.

But if you’re using QuickLoad to evaluate chamber pressures, you need a fair bit of precision. So when I’m running that old/new powder exercise I’ll demand that all charges be within three ticks of the highest precision that the FX-120i is capable of – either dead-on, or 0.02 grain under, or 0.02 grain over.

With that in mind, I set up the Chargemaster to throw those requisite charges – five of the old, five of the new – and set to seeing how many throws it would take…





Looked at one way, this test is entirely unfair to the Chargemaster. RCBS has never claimed anything other than 0.1 grain precision for that scale. Holding it to an accuracy level of 0.04 grains seems a very high bar, indeed. And yet the Chargemaster hit that level on ten out of 27 throws.

I’d call that good.

 

[JimSC]

I like my Charge Master but I find that maybe 2 to 3% end up way out there, sometimes off by more than a grain. Without fail these are overcharges. I double check on a A&D myself. Like Reagan said, trust but verify

 

[fatelvis]

In my eyes, it seems the variance in the lower charge weights are unacceptable, but from 30gr up, I consider the SD acceptable for my style of F-class shooting. I use my Charge Master for charges from 23.5-42 grains in my 223, 6BR, 6 Creed and 308 and am satisfied with it's performance. BUT... I only compete at 300 yds.

 

[Straightshooter1]

​

For a bunch of years now I have said that two things were game changers in my shooting world… the introduction of an accurate, reliable digital scale; and the accessibility of precise, easy-to-use chronographs.

Both of those, together, fundamentally changed how I approached handloading.

I’d now add a third – QuickLoad software. But that’s a story for another day.

Like many here, I began loading ammo a long, long time ago. And for most of us, that meant uncounted hours in front of an analog beam scale. That 10-10 scale of mine saw yeoman service across literal decades, and never gave a lick of trouble in all that time. When I open the door to my powder closet and see it resting there on the shelf, I cannot help but smile.

But I haven’t actually used it in years. The day my Chargemaster 1500 showed up was revelatory. And after using it for only a couple of loading sessions I knew I would never be going back.

For all its benefits of speed and convenience, though, the Chargemaster didn’t bring any improvement in precision – it came claiming the same 0.1 grain accuracy that its numerous analog predecessors had long offered. It would be many more years before affordable technology would grant us the ability to look back and see what we had.

Nowadays, my scale of choice is an A&D FX-120i. That’s not the only good scale out there, of course. There are even better, pricier models available – the esteemed Sartorius comes to mind. But the FX-120i strikes a good balance between price and performance. And it’s popular among many serious handloaders (I say “serious” not as a slight to anyone who doesn’t choose it, but rather simply as a nod to its price point… I don’t know of anyone who would pay the coin for one if they weren’t pretty serious about their handloading).

More particularly, one of the benefits of a laboratory-grade electromagnetic force restoration scale like the A&D or the Sartorius is that it allows you to evaluate their older strain-gauge (or analog) brethren. The much deeper levels of precision a lab balance offers – 0.02 grain in the FX-120i or 0.01 grain in the Sartorius – allow us to, finally, judge the efficacy of those older scales.

With that in mind, I decided to throw a few charges with the Chargemaster, weigh them on the A&D, and see what I got. It’s an interesting experiment… the Chargemaster, after throwing its charge, sits there with a number painted on its LCD screen. That number seems solid, resolute, unequivocal. You very much have the feeling that that number is the number.

And then you lift the pan and carefully place it on the A&D…

View attachment 1253568



The Chargemaster actually acquits itself pretty well. Of 26 charges thrown, only one – the 10.72 gr charge in the third group – was outside its 0.1 grain spec, and that just barely. The average throws are very close to the target weight. And the standard deviation isn’t bad.

How about with a cartridge of higher capacity, using an extruded powder?


View attachment 1253569


Again, the Chargemaster does a pretty good job. Out of 20 charges thrown, only one – the 34.12 gr in the last group – is slightly out of spec.

I think it’s mostly a good-news story. The Chargemaster seems to reliably live up to its promises. I still use mine occasionally. Especially with larger capacity cartridges where a charge variation of some hundredths of a grain isn’t going to make much difference; or with loads where less precision is required.


One last twist, though… those of us who use QuickLoad know that you can (and should) tweak the Burning Rate factor in that software to dial in the particular powder lot you’re using. What I’ll do as I run near the end of a current lot of powder is build a handful of rounds of a known load, using known primer and brass, using the old powder; then load an equivalent number of rounds using the new lot of powder. Setting off those two groups in front of a chronograph will then give me a quick first baseline of where the new powder sits vis-à-vis the old lot.

But if you’re using QuickLoad to evaluate chamber pressures, you need a fair bit of precision. So when I’m running that old/new powder exercise I’ll demand that all charges be within three ticks of the highest precision that the FX-120i is capable of – either dead-on, or 0.02 grain under, or 0.02 grain over.

With that in mind, I set up the Chargemaster to throw those requisite charges – five of the old, five of the new – and set to seeing how many throws it would take…


View attachment 1253570


Looked at one way, this test is entirely unfair to the Chargemaster. RCBS has never claimed anything other than 0.1 grain precision for that scale. Holding it to an accuracy level of 0.04 grains seems a very high bar, indeed. And yet the Chargemaster hit that level on ten out of 27 throws.

I’d call that good.

Very nice Jager. Thanks for posting that.

I'm glad to see that in terms of SD's, it looks like your results are very much in line with my effort in evaluating my Chargemaster's accuracy with an FX-120i. In my view, the SD's weren't so important as the ES's of the charges as I found differences can be clearly exhibited on paper too in terms of group size.

You may have seen where I've posted my results, but I'll attach them here again just so it's easier to compare:

 

[jepp2]

And if you slow trickle the Chargemaster, it can be even more accurate. I ran that way a couple of years before I acquired my A&D.

 

[Ironman308]

Thank you for posting this. I used a tuned beam scale up to last year when I gave the Chargemaster a try. I tested it for several sessions with the beam scale and never looked back. Maybe I’ll step up my game to a better scale someday.

 

[Straightshooter1]

I feel the Chargemaster 1500 is plenty good for a great majority of shooting disciplines. But, for some of us that tend towards being OCD like when it comes to precision or perfection, then . . . ???

 

[PigButtons]

Thanks Jager for posting. It confirms my own findings as well. And I guess it depends on what you are trying to accomplish whether or not it is "good enough". When I didn't have anything to check it against it was "good enough", but now with the 120i my groups have shrunk considerably with my 22K Hornets. When loading a round where the charge is 10gr or less, 0.12 gr ES is huge, > 1%.

I guess my question is what level of accuracy do you now hold yourself to with the 120i? Both with powder charge and bullet weight. For me, I'm getting the number on the powder weight, and 0.1% on the bullets if I'm really trying to get the best my rifle can shoot. Some bullet lots are easier to get enough of one weight to make it practical.

 

[VA_XTC_Shooter]

I've seen a couple "tests" of the Chargemaster accuracy and all seem to agree, it's prety much a 0.1 gr scale.

When does 0.01 gr accuracy come in to play? Has anyone confirmed 0.1 vs 0.2 gr is out of the X or 10 ring?

I guess, asked a better way, when does the charge weight play a role reading 100ths of a grain vs 10ths?

 

[jackieschmidt]

How many shooters are demanding .01 accuracy in the powder charge but shoot .350+ agg bullets.

 

[Homerange]

CM throw accuracy is very much powder type specific in that coarse extruded powders are somewhat more difficult to control exiting the dispensing tube hence the MacD's straw mod and bushes were developed to obtain much better drop consistency.
My CM1500 straight outta the box caught a problem with my 505 that was throwing loads that had wandered off being accurate in a 223 but a good clean and retune of the 505 had it back to normal in short order.
LOL the 505 is back in its box and rarely ever use it now except as a sanity check for bushes in my MEC shotshell loader.

 

[Capt. Oblivious]

I acquired a CM lite end of last year and up till now I have been very happy with it, I tested it against some other known accurate scales and I doubt I can shoot the difference on a windy day. On most of my rifles even .3gr isn't really going to derail my train.

 

[Dgd6mm]

There's a lot of shooters/reloaders out there that can't shoot the difference. The ones that can will up their game with the FX scale where a certain discipline demands that kind of accuracy. An accurate powder charge is just part of the equation.

 

[Ned Ludd]

You can easily make a "crude" estimate of the effect of charge weight variance on velocity by multiplying [the extreme spread (ES) in powder weight divided by the total charge weight] by the average velocity. Let's say you had a .308 Win load that averaged 2750 fps with a 185 gr bullet seated over 43.8 gr Varget. If the charge weight ES was 0.2 gr (i.e. ~ median +/- 0.1 gr) the estimate would be:

[0.2 gr/43.8 gr] x 2750 fps = ~12.6 fps velocity variance solely due to charge weight variance.

This is not an absolute number, but works as a rough estimate to get some idea of how a given charge weight variance might affect velocity. In most precision circles, 0.2 gr ES in charge weight would be considered a LOT.

In contrast, there are those that weigh powder accurately to +/- half a kernel. If you do the same calculation above for that scenario, you're looking at an effect on velocity due to charge weight variance in the neighborhood of less than 1-2 fps. Not many reloaders can consistently obtain velocity ES values of less than about 5-7 fps, so that means that velocity variance due to charge weight variance is likely NOT their limiting source of velocity error. It might be neck tension (interference fit) consistency, primer selection, or something else entirely. However, the key point is that by weighing powder to a variance (error) level that has a theoretical effect on velocity significantly below the typical velocity ES values obtained with good loading technique, you are accomplishing two things. First, you never, ever have to worry about charge weight variance when behind the rifle at a match. Second, if you do ever get unacceptably high velocity ES/SD values, you can be certain the culprit is not charge weight variance, and start looking at other potential sources of error in order to rectify the issue.

The intended type of shooting and precision needs should dictate to what extent you are willing to go in term of accuracy/precision of powder weight measurement. Unless the highest possible precision obtainable is your goal, weighing powder to an extremely fine range such as +/- half a kernel will probably not be of much benefit.

 

[Tommie]

For us sub-caliber shooters .3 can be the difference between a safe load and a really bad day.

 

[divingin]

There's a lot of shooters/reloaders out there that can't shoot the difference. The ones that can will up their game with the FX scale where a certain discipline demands that kind of accuracy. An accurate powder charge is just part of the equation.

Well, yeah, but unless you start by fixing "part of the equation". you'll never make headway towards fixing "most of the equation".

Fixing the charge is probably the easiest to do, as it's readily evident when it's screwed up (the scale show it, assuming you measure after throwing the charge.) Much easier to ID than rifle or shooter problems.

 

[284winner]

I ran my Chargemaster next to both my beam scales. They were both identical in weighing powder charges. Haven't used my beam since.

 

[Dgd6mm]

I don't think it's the easiest. I think it's as easy as most of the other variables.

 

[1bamashooter]

I checked my CM on my FX120i when I got my AutoTrickler it was .2 to .4 gr difference

 

[JPTX]

I'm looking at getting one of the electronic powder dispensers. The ones I'm looking at are the RCBS CM 1500, CM Light, and the Matchmaster. The Matchmaster is more precise, but a whole lot more money. It will be used primarily with VM133 for Benchrest shooting the 6PPC @100 yards. I'd say the electronic measures are more accurate than a powder measure the throws by clicks or volume that was used for years at matches. In my calculations of 29 grains compared to 29.1 grains that is only .003 (3 thousandths) difference by weight. My question is, is the Matchmaster going to produce a noticeably better resulting group on paper? Question 2 - is the Matchmaster worth the difference? 3 - Does there seem to be a difference in precision results between the CM1500 and CM Light?