How Does The Chargemaster Do That?

[ED3]

@ED3 there are a number of threads on parameter adjustments, and these are very effective. You can run the first stage longer to achieve speed, but then be sure that the third trickling stage is activated at least 0.3gr before final to achieve precise trickling. Take a little time to experiment with these to find out what works best for your powders.

I played around extensively with the first 3 parameters, ultimately setting them conservatively- for precision vs speed, and have yet to get consistent or reasonable performance
The trickle stage is set to start at 1.0 gn before target wt.
My goal is to be approx. <0.10 gn off load requirement
One of 2 things happens:
Either it runs at slow speed(no trickle) to within 0.2 gn of set point, and over-throws by as much as .3gn, or it takes 20seconds+ for the last 1.0 gn, to trickle in which case it is typically ~.1 gn light.
Both these occur randomly on the same parameter settings using Varget.

A teaspoon and an auto-trickler looks better and better
I guess it's time to call RCBS.

 

[Tommie]

Reading this thread convinced me to stick with my beam scale.

 

[savagedasher]

I will pay shipping on all that are unhappy.
Larry

 

[Ledd Slinger]

Using the CM for a while on non-critical loads, I began to increase my cross-checks on a more sensitive scale. If all goes well the CM is within +/- 0.03gr, much tighter than the 0.1 resolution. How?
Using the more sensitive scale, I increased a load by 0.01 increments; weighing them on the CM I observed the reading did not change until a full 0.1 increase occurred. Meaning it truncates to the lower 0.1 gr, not rounding. This means during the incremental trickling/weighing stage it will not decide to stop until the full 0.1 programmed value is achieved vs stopping based on a rougher round off value. It also means it it overshoots by a few .01's then it doesn't care until a full 0.1 error occurs.

The most critical requirement to achieve uniform loads lies in achieving very fine charge increments during trickling. If you observe the last trickles, as long as these are typically small with no clumps of inadvertant vibration then the uniformity is much better than maybe expected. If the charging stops suddenly, probably vibration yielded a false reading and an undercharge occurred; but unfortunately an error will not be displayed because it though the false reading was correct.

Adjust to achieve very fine trickling; the uniformity is no better than the trickling increment. No vibration, watch for clumpling, and you should achieve excellent uniformity.

My CM is very accurate. I have cross checked the loads on my GemPro 250 which measures in .02 increments and the CM throws very consistent loads. I think it measures weight much more accurately than it displays on the screen. I have no trouble producing extremely accurate ammo with my CM. I have so much faith in my CM that I use it for ALL of my rifles, regardless of the importance I place on each rifle for making the shot count. I don't even cross check the CM weights anymore. My GemPro now sits collecting dust as an emergency backup.

Anyone who isn't seeing great consistency with the CM might not be modifying and setting it up properly. I did all the programming adjustments and added the straw before I ever threw my first charge with it. It has been extremely consistent every single time. I have thrown a LOT of charges. Too many to count, and it has NEVER overthrown the weight on me. It trickles kernels very slowly until it hits the .1gr of the set weight and stops perfectly. I have used powders of all types and densities from small inconsistently sized spherical powder like BLC-2 and small ball powder like AA1680 to short and long extruded kernels of all burn rates. Doesn't matter. It stays consistent through them all.

 

[Ledd Slinger]

I played around extensively with the first 3 parameters, ultimately setting them conservatively- for precision vs speed, and have yet to get consistent or reasonable performance
The trickle stage is set to start at 1.0 gn before target wt.
My goal is to be approx. <0.10 gn off load requirement
One of 2 things happens:
Either it runs at slow speed(no trickle) to within 0.2 gn of set point, and over-throws by as much as .3gn, or it takes 20seconds+ for the last 1.0 gn, to trickle in which case it is typically ~.1 gn light.
Both these occur randomly on the same parameter settings using Varget.

A teaspoon and an auto-trickler looks better and better
I guess it's time to call RCBS.

Programming is pointless if you do not have a straw inserted that protrudes about 1/8" past the factory threaded trickle tube. Setting the correct angle of the scale makes a difference as well. Add a slight slope with the adjustable legs where the rear is just a hair higher than the front, but make sure it is perfectly level left to right. I don't know exactly how you've adjusted your parameters, but it doesn't sound like they are correct. Im not positive now that it's been so long since I set my parameters, but i dont remember messing with the first 3 settings... My CM throws very fast until 1 or 2 gr away from target (can't remember exactly because I don't pay attention to how it throws anymore...), then slows until about .4gr away and jog trickles the last .4gr where it is only dropping 1 or two kernels at a time until it hits target weight. Charging time is very fast and accurate.

I really don't care if I'm a kernel over or under my target weight. When I've tuned a load for vertical with a ladder test, that one kernel won't make any difference in the world on paper.

I am at work overseas right now, but I will be home by next weekend. I will be loading some rounds for testing and I can post a pic of my parameter settings if you'd like? Perhaps they will help get your CM on track.

 

[ED3]

Programming is pointless if you do not have a straw inserted that protrudes about 1/8" past the factory threaded trickle tube. Setting the correct angle of the scale makes a difference as well. Add a slight slope with the adjustable legs where the rear is just a hair higher than the front, but make sure it is perfectly level left to right. I don't know exactly how you've adjusted your parameters, but it doesn't sound like they are correct. Im not positive now that it's been so long since I set my parameters, but i dont remember messing with the first 3 settings... My CM throws very fast until 1 or 2 gr away from target (can't remember exactly because I don't pay attention to how it throws anymore...), then slows until about .4gr away and jog trickles the last .4gr where it is only dropping 1 or two kernels at a time until it hits target weight. Charging time is very fast and accurate.

I really don't care if I'm a kernel over or under my target weight. When I've tuned a load for vertical with a ladder test, that one kernel won't make any difference in the world on paper.

I am at work overseas right now, but I will be home by next weekend. I will be loading some rounds for testing and I can post a pic of my parameter settings if you'd like? Perhaps they will help get your CM on track.

Thanks for your assistance.
I don't have a straw, but I did purchase the very popular brass insert before using the CM.
I will make the suggested checks and adjustments, and I look forward to your further advice.
Whether or not I keep this thing, I'll need to make it work right.
Regards,
Ed

 

[Ledd Slinger]

Thanks for your assistance.
I don't have a straw, but I did purchase the very popular brass insert before using the CM.
I will make the suggested checks and adjustments, and I look forward to your further advice.
Whether or not I keep this thing, I'll need to make it work right.
Regards,
Ed

I've never tried the brass insert. The straw works so well I don't have a reason to change it.

I will have to check my parameters to be sure. I think the video link I posted below is what I used years ago to program my CM. He only changes the first 2 settings. I remember it being very quick and simple. I never have clumps or overthrown weights.

 

[CharlieNC]

Ed3 something is still off in trickle mode. During this sequence you should observe minute drops, just as if you were doing manually. As noted insure proper level. Did you also get the small additional insert?

 

[Richard Coody]

anybody who thinks they are getting better than +/- 0.1 grains consistently with a chargemaster is fooling themselves.

my experience tells me even that is optimistic

 

[Milo 2.0]

anybody who thinks they are getting better than +/- 0.1 grains consistently with a chargemaster is fooling themselves.

my experience tells me even that is optimistic

I used to run 3 CM's, bought the auto trickler and fx120i.
I ran some serious tests with the cm's against the 120i as the gold standard, 3 powders.
Other than the standard overthrows, and we know they can be .4gr at times, the pull kernels with a wide blade tweezers trick, or dump and start over, they are easy to decipher and control.
The under throws is what I think some don't figure in, a full .1gr can slip through the cracks when clumps fall, seemingly disrupting the scale.
But, the number of charges spot on was remarkably high, enough that I made the decision to dump the expensive system and stay with the CM's, feeding it was way too slow for my operation.

 

[CharlieNC]

anybody who thinks they are getting better than +/- 0.1 grains consistently with a chargemaster is fooling themselves.

my experience tells me even that is optimistic

I just loaded 200 for upcoming Ftr match so I weighed each one on a scale with .01 resolution. Except for the obvious flyers caused by my vibration, every charge was +/- .05. I was a bit surprised and pleased, but not fooled. Inserts and careful tuning, not luck.

 

[savagedasher]

I loaded 35 for a match with a cm my ES was 8 on the 28 I shot . That is total .
But my cases had the internal volume checked .
The Same way of doing on another gun Without checking the internal the Es was 31 . The simple answer to me The internal volume was the problem .
The cm is fine when loading . Larry

 

[Ledd Slinger]

anybody who thinks they are getting better than +/- 0.1 grains consistently with a chargemaster is fooling themselves.

my experience tells me even that is optimistic

You must not have much experience with the CM....

 

[ED3]

Using the parameters suggested in the video, and the advice to level and slope the device, I performed a test:
25 throws each-
unmodified throat,
the brass insert,
and
the McD straw;

'round robin'- 5 throws each mode, for a total of 75 throws.

The performance I get is nothing like the video.
While the straw was the most consistent, and accurate, it fas far too slow to be useful loading anything but a handful of ammo.

I recorded the throw times (from hitting the 'dispense' button to finish beep) of all 75 throws.


The throw times of the unmodified throat averaged about 12 seconds, but consistently over-threw with these parameters.

The times for the brass insert were approx 14 seconds, and over threw most times.

The times for the straw were 30 - 40 seconds, a typical time being about 32 seconds,with one as fast as 5 seconds, and the longest being 64 seconds; most of the time spent in the trickle mode, yet overthrowing 10 of 25 times.

I later experimented with reducing the 3rd value- which pertains to the amount trickled. Making .1gn adjustments had little effect until the value got so low, it overshot the end point by several tenths. I could not find a happy medium that would hit at, or slightly below target within 20 seconds using the straw...

Also worth noting is the rounding error (if that's the correct term)...
While it's not a defect, per se,
the CM scale would display 42.8 gn (my programed target wt.) for throws that were anywhere from 42.76 to 42.84 on the AnD Fx scale.

That in and of itself is not a insurmountable issue, as I never intended to use the CM without a finishing trickle and the Fx scale, but it does seem to counter claims that this will produce the most accurate ammo, with no further attention.

What is an issue is the inconsistently long throw times; sitting and watching this thing do next to nothing for 20-30 seconds each throw is not acceptable when loading 200 rounds for the weekend.

 

[CharlieNC]

Ed3 it sounds like you are misinterpreting the definition of the parameters; these are grains below the target at which time the speed is reduced. So when you decreased parameter 3 to speed up, you get overthrows because it cannot slow down that quickly. Because of the inertia and delayed response, the actual timing is shorter vs the programmed time. For faster charging decrease parameter 1 to run full speed longer(I use 9.5), then parameter 2 before switching to slow ( I use 3.75), and then you want to enter trickle mode around .3-.5gr before target ( I use 1.50). So my strategy is run the first stages as long as possible for speed, then enter trickle mode .3-.5 before target to balance speed with accurate trickling. If you get overthrows after being in trickle mode for at least 0.2gr, then you have a mechanical dispensing problem.

 

[Richard Coody]

i had one for a year or two before i found the autotrickler.

for me it was faster to charge with lee dippers on my gempro and trickle with my little dandy then wait for a charge from the chargemaster that i was going to have to trickle up anyway.

now i have fast and accurate

 

[Homerange]

Good feedback ED3, now you have some results to work with. Your powders will have some effect on how the CM performs but this too can be worked around with the setup, both settings and how it sits on the bench. With the straw, what opening did you use in the hopper ?
I have my CM dead level with the slight fall in the dispense tube incorporated into the CM design. I use a homemade insert spun from a piece of alloy and loosely based on the design of the brass inserts available online. How the unit dispenses in trickle and twitch modes is critical to accuracy IMHO. It must dispense just a kernel or two per twitch instead of any clumps which unless you're lucky will always end with overthrows.
You're close.....stick with it.

 

[ED3]

Ed3 it sounds like you are misinterpreting the definition of the parameters; these are grains below the target at which time the speed is reduced. So when you decreased parameter 3 to speed up, you get overthrows because it cannot slow down that quickly. Because of the inertia and delayed response, the actual timing is shorter vs the programmed time. For faster charging decrease parameter 1 to run full speed longer(I use 9.5), then parameter 2 before switching to slow ( I use 3.75), and then you want to enter trickle mode around .3-.5gr before target ( I use 1.50). So my strategy is run the first stages as long as possible for speed, then enter trickle mode .3-.5 before target to balance speed with accurate trickling. If you get overthrows after being in trickle mode for at least 0.2gr, then you have a mechanical dispensing problem.

Initially I left #3 alone. Only after watching it trickle for 20-30 seconds did I start to experiment.
The trickle mode, controlled by parameter 3 seems to be where the issue is.
When #3 is set at the recommended ~1.0gn, it does fine through thought the faster stages, Then it spends 20+seconds trickling...whether that is set at 1.0 gn, or 0.3 gn. When I go lower, it over throws by ~0.1gn.
I realize there is inertia, and some anticipation must be programmed, but this thing is all, or nothing for the last ~1.0 gn.

 

[ED3]

Good feedback ED3, now you have some results to work with. Your powders will have some effect on how the CM performs but this too can be worked around with the setup, both settings and how it sits on the bench. With the straw, what opening did you use in the hopper ?
I have my CM dead level with the slight fall in the dispense tube incorporated into the CM design. I use a homemade insert spun from a piece of alloy and loosely based on the design of the brass inserts available online. How the unit dispenses in trickle and twitch modes is critical to accuracy IMHO. It must dispense just a kernel or two per twitch instead of any clumps which unless you're lucky will always end with overthrows.
You're close.....stick with it.

I don't feel I've gained anything.
When it takes 30 seconds to drop a charge, and 25 seconds are spent in the trickle mode, adding the last ~gn. something is wrong. When I experiment and reduce parameter 3, nothing changes until it gets so low it doesn't even enter trickle, and gives me an over charge.

 

[ED3]

i had one for a year or two before i found the autotrickler.

for me it was faster to charge with lee dippers on my gempro and trickle with my little dandy then wait for a charge from the chargemaster that i was going to have to trickle up anyway.

now i have fast and accurate

Sharing your reasoning, I ordered an auto-trickler, and a set of Lee dippers late last week. I just want to get this thing working so it either can serve as a back up, or more likely be able to sell it with a clear conscience.