Rcbs Chargemaster versus Varget

Z

zanemoseley

New member
So I bought a Chargemaster in late May but haven't used it a whole lot. As I've used it more I realize it doesn't work real well with varget since its extruded, kind of a bummer when you drop over $300 on something.

I contacted Rcbs tech support and they recommended a few general things as well as the Mc.Donalds straw trick in the feed tube. Here are my results before and after the straw, 50 sequential loads of 42.0 grains, my standard .308 target load.

Stock:

42.0 - 16 32%
42.1 - 6 12%
42.2 - 10 20%
42.3 - 11 22%
42.4 - 3 6%
42.5 - 4 8%


Mc.D's Straw:

42.0 - 27 54%
42.1 - 10 20%
42.2 - 7 14%
42.3 - 5 10%
42.4 - 1 2%
42.5 - 0 0%


It obviously helped a bit but it's still overcharging about half of the loads. Would you guys be happy with this performance? Yeah it's not hard to pinch off a little powder from the pan but kinda feel like I shouldn't have to do this on a $300 measure, the whole reason I got this was for speedy accurate rifle loads using varget.

I'm not sure what's gonna happen if I push RCBS tech support, they may want me to send it in.
 
Looks like a single-tailed distribution to the high side. It suggests the machine tries to stop at the right weight, but inertia is carrying it over. I also wonder if scale load cell hysteresis is a factor. If you have one, set up a second scale and see if it confirms the first scale's readings.
 
I have been using my Chargemaster for around 8 years. I haven't run any Varget through it, but lots of other stick powders, some long, some short. I don't use the straw, but at most maybe 5% go over (almost never have any under weights since it continues to disburse). And never more than 0.2 gr, usually only .1 gr.

Yours doesn't seem to be performing like it should be. You can change the software tuning, if you feel adventurous.
 
I don't have an rcbs but I do have the hornady. For the hornady there are a couple of options that if the equivalent exists for rcbs, it may help. The first is when it starts to trickle, the second is the speed it trickles at. Does rcbs have the ability to start to trickle sooner?
 
I have the Lyman version, and it also tends to overthrow Varget and other stick powders by 0.1 and occasionally 0.2. I just set it to throw light by 0.1 and trickle. And I haven't used the straw.
 
I haven't seen any options for it to trickle sooner or later in the charge.

To me the Chargemaster is a bit twitchy when it comes to trickling at the end. I think it would work better if it would rotate very slowly like you do by hand, instead it kind of twitches about 1/10 or 1/8 of a rotation at a time, not very slowly either.
 
I too have a ChargeMaster 1500 and have been using it for years. Most of the time I do not need to re-throw the charge because it is spot-on.

Those time I do, I just read the charge and throw the powder back into the bin and restart the trickle.

Every time I set it up for use, I calibrate the scale and let it sit for about 30 min. That is to warm up the sensor at the bottom of the scale.

I find when it does drop a grain too much, it is because I have not taken the time to shake the canister of powder to break up the clumps that are sticking together because of the change in moisture in the air. Yes, there is a Santa Clause and a temperature change.

This appears to be the major problem when you do not take the time to prep your powder and just pour it into the bin.

Jim
 
Interesting link, I hadn't seen the brass fitting modification yet. Might give it a try tomorrow. Would definitely be worth a $5 part of it works well.
 
Looking at that link, he talks about a setting that changes the trickle speed. Essentially it dispenses at full speed up to a certain point and then slows down. Same thing as the hornady. I'd try that.
 
I wonder if it allows it to go slower than stock. Stock, it starts fast and goes slow at the end. It never overcharges a load because it's waited too long to slow down. I could see it helping it there is a slower speed than it currently uses.
 
The above video is very good at showing how and where to set the settings. Also I made 2 straws. The one I use for the ball powders has a smaller cut-out at the hopper end and the other has a larger cut-out for stick powders. It seems to control the flow better.
 
I have one that I bought way back say 13 or so years ago, no problem, but been idle for awhile, until this year.

You gave me an idea might bring the RCBS beam balance scale out and check the weight of the throws.

Good deal either way, and have to agree that a $300.00 scale should be closer then say a $30.00 one.

Actually the list price on RCBS is closer to $500.00:eek:


Jeff
 
Ok guys I tried something else I saw online and its the best yet. Basically instead of a short section of tube you cut a piece that is long enough to go all the way back to the section of tube that picks up the powder. I cut a slot a bit less than 1/8" wide to reduce the flow of powder a bit in the tube, honestly I think I could have gone even tighter however it definitely helped the performance with varget.

42.0 - 36 72%
42.1 - 12 24%
42.2 - 2 4%

 
That will slow the powder pick up rate, but will also slow the dispensing rate overall.

The hose barb weight won't stress a stepper motor or any other ECM (electronically commutated motor—it would stall trying to go fast if the mass was a problem) as it's current is limited internally. It's not like an induction motor that draws a lot of extra current when it's stalled. However, the extra mass could add bearing wear. So you could, instead, try a Nylon hose barb fitting. They had them at Lowe's the last time I looked. Same thing, but in translucent white plastic. Much lighter.
 
When I got mine I has some issues with it over charging every now and again.

Is the surface the scale is on level? That seemed to be the cause of my problems with various powders including Varget. I'll still occasionally get an overcharge but its rare maybe 2 overcharges per 100 drops. No straws, no reprogramming.

Another tip I was given by someone for a newer dispenser was to load the hopper up with powder, set a rather large charge, and run that powder through 2 or 3 times. Something about the powder providing a sort of lubrication to the aluminum tube and allowing the powder to more freely flow through it. I did it the one time as it seemed like more like voodoo than science.

All I know is mine works damn near flawlessly.
 
I throw a lot of Varget out of mine - rarely get an overcharge anymore (did the straw trick and reprogrammed it), and if I do it is only by .1 grain, which is inconsequential as it is so I usually just load it up.

I have found that I don't snap the clear cover closed, rather just swing it over while it is charging. The little vibration it creates when the detents are disengaged would sometimes cause a little extra powder at the mouth of the dispensing tube to trickle out. I also do not have moving air in the room when I'm using it as I found that to cause fluctuations in the scale readout.
 
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