RCBS ChargeMaster 1500: Some Comments to Improve Consistency

[rg1911]

I've noticed that RCBS ChargeMaster 1500s appear frequently for sale on the forum. In case the reason for selling is erratic measurements, I would like to offer some comments based on my experience.

About the first thing I did when I got my unit was to find the hacks to speed it up. As I used the unit, I become increasingly frustrated by the large number of over- and under-throws it gave. The over-throws were particularly annoying because it meant the charge had to be redone. I was just about to ditch the unit when I thought I'd try reducing the speed.

I may have erred a bit on the side of caution, but since the change, I have not seen a single over- or under-throw. I will cheerfully live with the slow-down since it saves me from weighing each charge by hand. This is not enjoyable when I'm loading 100 260REM for a match.

I also installed the standard reducing sleeve and the smaller sleeve, offered by Hide member MDM:

https://www.snipershide.com/shooting/threads/chargemaster-reducing-insert.6254583/#post-6254583

Key ChargeMaster Parameters with Default Settings:

HSB_A1 (15.68) Grains under target weight to go from full to high speed
HSB_B1 (3.42) Grains under target weight to go from high to slow speed
BSP_C1 (1.08) Grains under target weight to go from slow to final trickle speed

My current settings (using Varget and H4350) are:

HSP A1 - 9.00
HSP B1 - 3.50
HSP C1 - 1.40

Sources of information included:

https://www.snipershide.com/shooting/threads/fyi-chargemaster-can-be-re-programmed-new-trick.355/

https://texashuntingforum.com/forum/ubbthreads.php/topics/6409969/1

https://www.accurateshooter.com/gear-reviews/speed-up-your-rcbs-chargemaster/

Cheers,
Richard

 

[straightshooter1]

I've noticed that RCBS ChargeMaster 1500s appear frequently for sale on the forum. In case the reason for selling is erratic measurements, I would like to offer some comments based on my experience.

About the first thing I did when I got my unit was to find the hacks to speed it up. As I used the unit, I become increasingly frustrated by the large number of over- and under-throws it gave. The over-throws were particularly annoying because it meant the charge had to be redone. I was just about to ditch the unit when I thought I'd try reducing the speed.

I may have erred a bit on the side of caution, but since the change, I have not seen a single over- or under-throw. I will cheerfully live with the slow-down since it saves me from weighing each charge by hand. This is not enjoyable when I'm loading 100 260REM for a match.

I also installed the standard reducing sleeve and the smaller sleeve, offered by Hide member MDM:

https://www.snipershide.com/shooting/threads/chargemaster-reducing-insert.6254583/#post-6254583

Key ChargeMaster Parameters with Default Settings:

HSB_A1 (15.68) Grains under target weight to go from full to high speed
HSB_B1 (3.42) Grains under target weight to go from high to slow speed
BSP_C1 (1.08) Grains under target weight to go from slow to final trickle speed

My current settings (using Varget and H4350) are:

HSP A1 - 9.00
HSP B1 - 3.50
HSP C1 - 1.40

Sources of information included:

https://www.snipershide.com/shooting/threads/fyi-chargemaster-can-be-re-programmed-new-trick.355/

https://texashuntingforum.com/forum/ubbthreads.php/topics/6409969/1

https://www.accurateshooter.com/gear-reviews/speed-up-your-rcbs-chargemaster/

Cheers,
Richard

I've tuned my CM 1500 very similar to this and it actually does a pretty good job for consistent charges. However, for me it's not good enough. The+/- .1 gr resolution of the weighing mechanism gives more variance than I want. So I use a second electronic scale that measure to a +/- .02 resolution.

For example, if I want 44.0 grs my CM will show 44.0, but when on my other scale it's 44.08 grs or it'll be 43.92 grs and various weights in between. But that's an ES of .16 grs , which can produce a vertical spread with the powders I use in just 100 yds. But using my second scale and removing or adding a few kernels to get closer to that 44.0 grs I'm after, I can get within +/- .02 for an ES of .04 grs. The results on paper and my chrono are much more satisfying . . . for me.

 

[lash]

Something is wrong with the numbers that you typed, see my bolded and red font in your post below. You are talking about 1.6g (10 times .16g) in variation, which I know is not what you meant.

I've tuned my CM 1500 very similar to this and it actually does a pretty good job for consistent charges. However, for me it's not good enough. The+/- .1 gr resolution of the weighing mechanism gives more variance than I want. So I use a second electronic scale that measure to a +/- .02 resolution.

For example, if I want 44.0 grs my CM will show 44.0, but when on my other scale it's 44.8 grs or it'll be 43.2 grs and various weights in between. But that's an ES of .16 grs , which can produce a vertical spread with the powders I use in just 100 yds. But using my second scale and removing or adding a few kernels to get closer to that 44.0 grs I'm after, I can get within +/- .02 for an ES of .04 grs. The results on paper and my chrono are much more satisfying . . . for me.

 

[straightshooter1]

Something is wrong with the numbers that you typed, see my bolded and red font in your post below. You are talking about 1.6g (10 times .16g) in variation, which I know is not what you meant.

Thanks. You're right . . . I got the decimal point in the wrong place.

44.0 - 43.92 = .08
44.08 - 44.0 = .08

.08 + .08 = .16 gr spread.

I think that's how the arithmetic works.

Addendum: making correction to the decimal place as it needs moving over on place from .8. And thanks to lash for straightening me out on this.

 

[Holliday]

I've tuned my CM 1500 very similar to this and it actually does a pretty good job for consistent charges. However, for me it's not good enough. The+/- .1 gr resolution of the weighing mechanism gives more variance than I want. So I use a second electronic scale that measure to a +/- .02 resolution.

Can I ask what second scale you are using/ recommend?

 

[lash]

Thanks. You're right . . . I got the decimal point in the wrong place.

44.0 - 43.2 = .8
44.8 - 44.0 = .8

.8 + .8 = 1.6 gr spread.

I think that's how the arithmetic works.

Okay, that’s not the way I thought this would go. I hate to keep harping on this, but a 1.6gr spread is huge. I have to ask you for more verification.

My experience with the CM 1500 is that it is accurate to +/- 0.05gr. This means that my scale will show 41.8g when the actual measurement could be 41.75-41.85. Many checks of its results bear this out for me and my results on paper show the same.

I also slowed mine down and added the inserts from MDM here on the Hide. While that does mean I don’t get the speed I would prefer, it also means that I get about one overthrow in 100+ drops. My OCW nodes are larger than the variation in the scale measurements.

Are there better scales out there? Absolutely. But this does what I need all day long without issue, so it’s my choice.

 

[straightshooter1]

Can I ask what second scale you are using/ recommend?

It's an old GemPro 250

 

[TxWelder35]

Thanks. You're right . . . I got the decimal point in the wrong place.

44.0 - 43.2 = .8
44.8 - 44.0 = .8

.8 + .8 = 1.6 gr spread.

I think that's how the arithmetic works.

You need a new CM if yours is that far Off

 

[straightshooter1]

Okay, that’s not the way I thought this would go. I hate to keep harping on this, but a 1.6gr spread is huge. I have to ask you for more verification.

Yes, I'd say it is "huge". This is what I get for tying to rush a response when my mind in on mother's day events. I'm embarrassed. 1.6 isn't correct. Originally I had the .16 gr number correct, it's the decimal point on the other two number that should have been moved to show .08 grs. Guess that's why people my age are best retired.

But I'll still stand by what I said about .16 gr spread showing up at 100 yds (especially if one's load is not in the middle of a node) and on the chrono too.

Thanks again, as I really hate confusing anyone.

 

[straightshooter1]

You need a new CM if yours is that far Off

For sure!!!

 

[flyright]

When I weigh my CM throws on my FX 120i they are always within .04. The CM rounds .06 up to the next .1 and .04 down. A .05 will cause it to vacillate. So, 2 or 3 kernels off is not too bad. I did the reprogramming to the CM and it put a big halt to the overthrows. I'd have no problem using it if my FX V3 went down.

Edit: So, .08 ES is within advertised accuracy but I'd guess it's better than that about 75% of the time - SWAG.

 

[lash]

Yes, I'd say it is "huge". This is what I get for tying to rush a response when my mind in on mother's day events. I'm embarrassed. 1.6 isn't correct. Originally I had the .16 gr number correct, it's the decimal point on the other two number that should have been moved to show .08 grs. Guess that's why people my age are best retired.

But I'll still stand by what I said about .16 gr spread showing up at 100 yds (especially if one's load is not in the middle of a node) and on the chrono too.

Thanks again, as I really hate confusing anyone.

It’s all good. At first I was sure that’s what you meant anyway. Now that it’s cleared up, no harm, no foul.

 

[karb]

I bought my CM around 2013. Some powders would throw exact input numbers. Then there were powders like varget that would stack up in the feed tube, and trip out of the dispenser in a clump when the CM was hunting for the final .2g. So yeah, I'd get some serious overthrows....even with a straw jammed inside to smooth the operation. Then recently, I was on Amazon, and found this... ordered....and it was the solution for throws (if the machine is giving false weight then I'm unaware, and would be a separate issue).

Amazon.com : MK Machining - RCBS Chargemaster Inserts - Hornady Auto Charge Antistatic Inserts - Powder Tube Inserts : Sports & Outdoors

Amazon.com : MK Machining - RCBS Chargemaster Inserts - Hornady Auto Charge Antistatic Inserts - Powder Tube Inserts : Sports & Outdoors

www.amazon.com

 

[straightshooter1]

When I weigh my CM throws on my FX 120i they are always within .04. The CM rounds .06 up to the next .1 and .04 down. A .05 will cause it to vacillate. So, 2 or 3 kernels off is not too bad. I did the reprogramming to the CM and it put a big halt to the overthrows. I'd have no problem using it if my FX V3 went down.

Edit: So, .08 ES is within advertised accuracy but I'd guess it's better than that about 75% of the time - SWAG.

Yes, my CM does better than that most of the time. That's why I feel that the CM actually does a pretty good job for the most part and suitable for most shooters. But my goal is to produce as consistent loads as I can where I see regular single digit SD's and ES's in the low teens if not single digits in my chrono data. Then I feel more confident that I can understand what I see on paper at distance. I'm not a great marksman, but at least I can get good loads and know that it's not the loads to blame for any of my poor results I see on paper.

 

[Milo 2.5]

When I weigh my CM throws on my FX 120i they are always within .04. The CM rounds .06 up to the next .1 and .04 down. A .05 will cause it to vacillate. So, 2 or 3 kernels off is not too bad. I did the reprogramming to the CM and it put a big halt to the overthrows. I'd have no problem using it if my FX V3 went down.

Edit: So, .08 ES is within advertised accuracy but I'd guess it's better than that about 75% of the time - SWAG.

I bought one of the first Auto trickler systems, I had 3 CM's at the time. Sold one CM right off, kept 2 to feed the auto trickler. 2 afternoons in a row, I ran head to head tests from the CM's to the fx120i. I tested 3 powders, VV N 550, IMR 4451, and IMR 7977. My CM's were optimized for 40 gr charges, with inserts. I have long thrown my data, and came to the conclusion that the AT was not going to give me the gains I sought, and sold it.
My findings were 92% of CM charges were spot on, and clearing overloads was easy with a wide blade tweezer, esp once you figure the kernel weight, which I feel you do not need a lab grade scale for that. So once I figured in overload clearances that had been rectified, now I was at 97% on, so now the CM is even more of a viable product.
The disturbing part was under throws, up to the full .1gr, my 2 CM's were not capable of the numbers you post concerning under charges, it seemed the under throws were the result of a clump of powder hitting at once and giving the desired number w/o a correction. I have loaded single digit SD numbers for yrs with a CM, I do decent load workups.
That said, I prepaid for a V3 last month from CE, but I will still keep 3 CM's here for 223 ammo, I have a friends CM on loan, doubt he will ever see it again.

 

[Holliday]

I bought one of the first Auto trickler systems, I had 3 CM's at the time. Sold one CM right off, kept 2 to feed the auto trickler. 2 afternoons in a row, I ran head to head tests from the CM's to the fx120i. I tested 3 powders, VV N 550, IMR 4451, and IMR 7977. My CM's were optimized for 40 gr charges, with inserts. I have long thrown my data, and came to the conclusion that the AT was not going to give me the gains I sought, and sold it.
My findings were 92% of CM charges were spot on, and clearing overloads was easy with a wide blade tweezer, esp once you figure the kernel weight, which I feel you do not need a lab grade scale for that. So once I figured in overload clearances that had been rectified, now I was at 97% on, so now the CM is even more of a viable product.
The disturbing part was under throws, up to the full .1gr, my 2 CM's were not capable of the numbers you post concerning under charges, it seemed the under throws were the result of a clump of powder hitting at once and giving the desired number w/o a correction. I have loaded single digit SD numbers for yrs with a CM, I do decent load workups.
That said, I prepaid for a V3 last month from CE, but I will still keep 3 CM's here for 223 ammo, I have a friends CM on loan, doubt he will ever see it again.

 

[Milo 2.5]

View attachment 7323099

Have you and I had a "science" chat before? I really don't think gathering data is science so to speak, I just had to know how the CM's measured up. The CM's sitting on my bench are #s 4 & 6, and they have ran flawless for a long time, not all have been so reliable, so not sure if my data is valid when comparing CM's. Some guys just get flat out lemons, my # 5 was one, no matter how often I wiped it down with a dryer sheet, all the other steps I took, it was a piece of shit. I recall trying to get a replacement on it, was asked the serial number, it was made over 1 yr ago, even though I had owned it for 5 mos. No go on replacing, go off mfg date, thing sat in a warehouse too long.

 

[flyright]

My V3 may have decreased my SD's/ES's as they have gotten slightly better. However, I think some other improvements in my reloading techniques over the last couple of years might be part of it or a combination. A BR shooter friend of mine thinks there are too many other variables that make worrying about a kernel or 3 of powder insignificant. Neck tension is one he frets over along with metallurgy and volume of cases. He culls more cases than he uses and wins quite a bit. That said, I don't know any BR or F class shooters using a CM but I've only heard from a few...

 

[Holliday]

Have you and I had a "science" chat before? I really don't think gathering data is science so to speak, I just had to know how the CM's measured up. The CM's sitting on my bench are #s 4 & 6, and they have ran flawless for a long time, not all have been so reliable, so not sure if my data is valid when comparing CM's. Some guys just get flat out lemons, my # 5 was one, no matter how often I wiped it down with a dryer sheet, all the other steps I took, it was a piece of shit. I recall trying to get a replacement on it, was asked the serial number, it was made over 1 yr ago, even though I had owned it for 5 mos. No go on replacing, go off mfg date, thing sat in a warehouse too long.

I don’t do much with mine and I don’t have anything to check it against. I do warm it up 30 mins to an hour before use and recalibrate at every use. Other than that I keep my cell phone away, the air still and de-static myself on a faucet then remove my shoes. I also empty it when not in use.

 

[rg1911]

Let me add that I know the ChargeMaster 1500 is not the most accurate scale on the planet (RCBS says it's accurate to +/- 0.1 gr, the same as my tweaked 10-10 scale). For instance, I have read that G. David Tubb weighs his loads to the granule.

A few personal points:

- I am not by any stretch of the imagination even close to Tubb's league.
- I'm running the 260REM in an AR10 with a Krieger barrel; not a match bolt-action.
- I'm using this combination in our local Precision Rifle matches from very unsteady (for me) rests that pretty much negate any accuracy improvements based on absolute charge consistency.

In short, as I nudge 70, complete with bad arthritis, my goal is to enjoy my shooting experiences. The ChargeMaster's accuracy is all I need.

Cheers,
Richard