RCBS Chargemaster Combo... Dilemma

[vman]

Hey guys

Thought I would post this up here so I could get some feedback from long term Chargemaster users.

Heres the scenario. Chargemaster is brand new and set up on the reloading bench. No other electrical devices in the room, besides a light on the ceiling which is a non-fluorescent globe.

So I have a friend over who Im showing the ropes of reloading and what a brilliant oportunity to test out my brand new chargemaster.

For the sake of science i break out the balance beam and demonstrate how I used to measure powder compared to this new device. So i dial in 46.6gr Varget on the CM Combo and out it pours. I zero my balance beam scale, and then set up the weights to 46.6gr. I put the powder from the chargemaster onto the balance beam and Im suddenly reading about 46.9gr on the balance beam. This 0.3gr inconsistency seemed to be about the margin of error every time I checked this.

Baffled I pulled out a Lapua 155 Scenar, which came out to about 154.4 on both the balance and the chargemaster. I put a 175smk on both and hey presto they both weigh the projectile at 175.1gr. I did the same for a Berger 185 VLD and both measuring devices were spot on.

I went back to the CM and dialed in 46.6 of powder and let it do its thing. Beep!. Measure on the balance beam and hey its 46.9gr.

Here are the conditions. This testing was all done within the same 30 minute time frame. The bench was not moving. Airflow was not crazy. The chargemaster is stock standard, no changes made to the programming. The CM was calibrated using both 50g and 100g.

Now, if the projectile were coming up with bogus numbers, I would be suprised but they arent. Can anybody shed some light on what I consider to be a mysterious event. I feel I now have to go and spend extra time researching what my "true" nodes actually are as Im totally baffled!

Thanks in advance fellas

 

[ChrisGarrett]

Re: RCBS Chargemaster Combo... Dilemma

The CM-1500 can drop extra powder, especially stick powders, which 'fall' off the lip of the spout and increase the weight.

It's a random thing.

When using sticks, I generally set my target weight to drop '.1gr' less than I want. So if I'm shooting for 45.0grs, I'll set the CM-1500 to 44.9grs and more often than not, I don't have to fish any kernels out of the pan, or trickle up, but at times I have to.

Another thing I do, is after the powder finishes dropping, I'll lift the pan off the scale quickly and let it resettle back onto the scale, getting a 'true' reading. The weight can change doing this, because the sensor isn't able to differentiate single kernels which get dropped, after the fact and after the scale reaches that target weight.

Now, if you're getting two different weights, with the same pan of powder, on both of your scales, something is up.

You can use check weights to find out which one is wrong.

Chris

 

[PLeighton]

Re: RCBS Chargemaster Combo... Dilemma

Just use the Chargemaster and forget about it.
If you did all of your development and testing with the CM, the load measured on the CM is the correct one.

The weight is relative as long as it is consistent.
It could read two pounds or seven red skittles, all that matters is that you can get the same reading every time.

If it still bothers you, get a set of calibration weights and test each scale.
Or, just use the CM calibration weights and see what your beam scale reads.

As a point of trivia, I measured my CM calibration weights at work on a scale capable of .01 gram incriments and both 50g weights measured 50.07g.

 

[samnev]

Re: RCBS Chargemaster Combo... Dilemma

I'd give RCBS tech a call they have always been very helpful. You have a weird problem going on so go to the experts at RCBS.

 

[johncx0]

Re: RCBS Chargemaster Combo... Dilemma

I found a great idea on the Hide a while back that really helps my Chargemaster drop an accurate load. Get a large plastic drinking straw from McDonalds, Wendys etc. Cut two pieces about 3/8 inches long. Split one side of the first piece, and slide it over the other piece. Insert both in the "spout", flush with the end. This allows the feed to drop smaller amounts rather than the inside threads dropping a pile on each jog. I can run at least 50 rounds without an overage.
You may find a straw that fits without adding the split extra piece?

 

[vman]

Re: RCBS Chargemaster Combo... Dilemma

I will have a look into it johncx0

One thing i just thought of, is measuring the calibration weights that come with the combo against the scales i have at work that tend to go out to 4 decimal places.

Provided it shows a high level of accuracy against the scales at work I wont worry about it further as it may be an issue with the balance beam.

 

[ReaperDriver]

Re: RCBS Chargemaster Combo... Dilemma

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: johncx0</div><div class="ubbcode-body">I found a great idea on the Hide a while back that really helps my Chargemaster drop an accurate load. Get a large plastic drinking straw from McDonalds, Wendys etc. Cut two pieces about 3/8 inches long. Split one side of the first piece, and slide it over the other piece. Insert both in the "spout", flush with the end. This allows the feed to drop smaller amounts rather than the inside threads dropping a pile on each jog. I can run at least 50 rounds without an overage.
You may find a straw that fits without adding the split extra piece? </div></div>

I use the McD straw trick and its been a godsend when measuring stick powder like Varget or RL-15. I was going from an overcharge every 3-5 before to maybe 1 every 25-30 charges.

Another couple of CM tricks: 1) I got a $60 UPS from Best Buy that I run the CM on rather than just going right into the wall outlet. MUCH cleaner electrical current. The UPS is not as good as a pure component that is designed for cleaning up the current - but the UPS is also MUCH cheaper than a dedicated noise reducer.

2) I weighed out a custom check weight that's close to the charges I was throwing rather than the big 500 gram calibration weights. Take a penny, put a piece of tape on it, weigh it on the CM scale and write that weight down on the tape. My penny is exactly 39.9 gr. I use that often throughout the loading to verify the scale is not drifting. It gives me a LOT of confidence when I can throw the penny into the pan and see that the weight is still spot on. I rarely even need to calibrate the scale anymore. I turn it on, throw the penny into the pan, see 39.9 and start loading. Mine rarely drifts.

I loves me my Chargemaster! Best $325 I've ever spent.

 

[Hookman]

Re: RCBS Chargemaster Combo... Dilemma

Good info - I can't wait to start using mine.

 

[vman]

Re: RCBS Chargemaster Combo... Dilemma

Thanks for the info guys, Il have a look into this straw trick... so whats it actually do? Im still struggeling to see what it does that helps.

I brought in both of my 50 gram weights to work and im very pleased to say that on my scale at work I got the following weights.

1) 50.0000
2) 49.9999 to 50.0000

So they are both spot on! Really happy about that

 

[Headgear]

Re: RCBS Chargemaster Combo... Dilemma

Vman, I read about the straw thing on another post or two. The way it helps is, the slick inside of the straw doesn't allow the powder to clump up at the end of the tube so when the CM jogs to trickle out the last .1 grain or so, only one or two sticks are at the end, able to fall out. The threads on the inside of the factory tube can allow a clump or log jam at the end of the tube and when the CM tries to trickle, a bunch of sticks can fall at once causing an over charge.

I haven't tried it yet but it makes sense. I've heard so many guys talk about it, it makes me wonder why RCBS doesn't make the last 1/2" or 3/8" of the tube smooth.

I just recalibrated my CM and love it. Now I need to swing by McD's and get me a diet coke and a fat straw

Hope I explained it correctly.

 

[Trapshooter12]

Re: RCBS Chargemaster Combo... Dilemma

I think one of the problems people are having with this machine is that they are in to big of a hurry and don't let it do it's job. I have paid close attention to the problems that people post and I have not had any. I pay attention when the powder is dropping and as the last kernels are dropping you can see that you are going to get an overcharge when the clump falls.

One thing I do is wait until the machine gives me the round count and then flips back to the weight again, at that time it will tell you if you are over weight.

 

[Kells81]

Re: RCBS Chargemaster Combo... Dilemma

When mine hits the target weight it beeps, shows count then goes back to weight. I have noticed it trips when it hits target and if you don't pay attention it will be a tad over sometimes. The Solution I found was the McDonald's straw which helped a bunch on drop time and accuracy. I check at start and mid point of my reloading on a RCBS scale and its right on the money with the scale.

 

[samnev]

Re: RCBS Chargemaster Combo... Dilemma

The McDonald straw really helps reduce the over charging.

 

[BigSoundRacing]

Re: RCBS Chargemaster Combo... Dilemma

McDonald straw is perfect for over charge - always wait for the round count followed by weight before removing from scale.

 

[ifarted]

Re: RCBS Chargemaster Combo... Dilemma

The weight is relative as long as it is consistent.
It could read two pounds or seven red skittles, all that matters is that you can get the same reading every time.

Good advice.
I believe the above quote is accurate if you never re-calibrate the scale.

Either way, you would never know the difference.
( dont tell him there is bacteria on his tooth brush...) hehe

 

[Quickdraw40]

Re: RCBS Chargemaster Combo... Dilemma

tag

 

[ReaperDriver]

Re: RCBS Chargemaster Combo... Dilemma

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Headgear</div><div class="ubbcode-body">Vman, I read about the straw thing on another post or two. The way it helps is, the slick inside of the straw doesn't allow the powder to clump up at the end of the tube so when the CM jogs to trickle out the last .1 grain or so, only one or two sticks are at the end, able to fall out. The threads on the inside of the factory tube can allow a clump or log jam at the end of the tube and when the CM tries to trickle, a bunch of sticks can fall at once causing an over charge.

I haven't tried it yet but it makes sense. I've heard so many guys talk about it, it makes me wonder why RCBS doesn't make the last 1/2" or 3/8" of the tube smooth.

I just recalibrated my CM and love it. Now I need to swing by McD's and get me a diet coke and a fat straw

Hope I explained it correctly. </div></div>

Yep, perfect!

 

[Headgear]

Re: RCBS Chargemaster Combo... Dilemma

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body"> One thing I do is wait until the machine gives me the round count and then flips back to the weight again, at that time it will tell you if you are over weight.
</div></div>

I sure as hell hope everybody does this because if you dont, you have no idea what it just dispenced and you did read/understand the directions if you don't do it this way.

 

[JNel]

Re: RCBS Chargemaster Combo... Dilemma

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: vman</div><div class="ubbcode-body">
For the sake of science i break out the balance beam and demonstrate how I used to measure powder compared to this new device. So i dial in 46.6gr Varget on the CM Combo and out it pours. I zero my balance beam scale, and then set up the weights to 46.6gr. I put the powder from the chargemaster onto the balance beam and Im suddenly reading about 46.9gr on the balance beam. This 0.3gr inconsistency seemed to be about the margin of error every time I checked this.

Baffled I pulled out a Lapua 155 Scenar, which came out to about 154.4 on both the balance and the chargemaster. I put a 175smk on both and hey presto they both weigh the projectile at 175.1gr. I did the same for a Berger 185 VLD and both measuring devices were spot on.

I went back to the CM and dialed in 46.6 of powder and let it do its thing. Beep!. Measure on the balance beam and hey its 46.9gr.

Here are the conditions. This testing was all done within the same 30 minute time frame. The bench was not moving. Airflow was not crazy. The chargemaster is stock standard, no changes made to the programming. The CM was calibrated using both 50g and 100g.

Now, if the projectile were coming up with bogus numbers, I would be suprised but they arent. Can anybody shed some light on what I consider to be a mysterious event. I feel I now have to go and spend extra time researching what my "true" nodes actually are as Im totally baffled!

Thanks in advance fellas

</div></div>

<span style="font-weight: bold">vman</span>- I have experienced this with my Chargemaster also. What I have noticed is the chargemaster is temp sensitive. I reload in room that is not always heated, so I have to preheat the room and turn on the scale for 20 minutes before I calibrate it. This solved the problem for me. Also keep an eye on the weight when the pan is removed from the scale. It should remain the same every charge. If it gets off .2 tenths of a grain you may want to recalibrate.

As for weighing bullets, they are not always going to be the exact advertised weight.