Hey guys, I have seen a lot of people asking about how to reprogram their RCBS Chargemaster 1500 to make it more accurate and faster. There isn’t a whole lot that needs to be written about reprogramming your RCBS Chargemaster so its more of a “Let me just show you” sort of scenario. The two key components are the straw and the software reprogramming if you want to improve your RCBS Chargemaster. Go to any McDonalds and grab a straw, its the perfect fit for the dispenser tube. Cut it leaving yourself a half inch to an inch or so of material sticking out the end of the dispenser tube. I’ve found that by cutting a saw tooth pattern into the end of the straw it helps as the RCBS Chargemaster is at trickle speed and it allows fewer grains to drop from the tube at a time.
Straw Modification for the RCBS Chargemaster
When you push the straw into the spout of the RCBS Chargemaster, push it all the way. You literally want to block the entire opening of the dispenser tube where the powder funnel is at the back of the RCBS Chargemaster. Mark the leading edge where it is exposed on the open half of the dispenser tube, and cut a small narrow opening in the tube for powder to drop into.
Reprogramming the RCBS Chargemaster
From there you just have to edit the software of the RCBS Chargemaster. To enter the programming settings press and hold the “EDIT MEM” and “ENTER” buttons at the same time. The first three settings are what you want to change. Program the first value to 7.0, the second value to 2.0, and the third value to 0.5. What you are telling the scale is at what point to shift speeds of the dispenser. These settings tell the scale to stay in high speed till within 7 grains of the desired charge, it will stay at medium speed until within 2 grains of the desired charge, and it will start to trickle at 0.5 grains under the specified powder charge. Special kudos to the guys at the Primal Rights forum for coming up with the magic size for the rear straw opening!
Electrical Line Noise
Another thing I’ve often read about is how noise, voltage fluctuations, and other electronic noise in the power lines can affect the RCBS Chargemaster and its accuracy. This typically manifests itself by the wandering scale zero. You would notice this after a charge is thrown, and you have dumped the pan. The scale should be reading exactly what the pan weighs in a negative number, because you zeroed the scale with the pan on it. If you notice that number changing by a few tenths of a grain higher or lower, that can be line noise. I looked into different ways of dealing with this and some can be very expensive and some much more affordable when trying to address Electro-Magnetic Interference (EMI) and Radio Frequency Interference (RFI) on the RCBS Chargemaster.
One of the easier solutions I found was at Radio Shack. Electronics stores often have what are called ‘chokes’ on the shelves. Its a two halve plastic snap on with a ferrite core that helps reduce and block those kinds of interference we just discussed. I gave it a whirl and bought a two pack. I snapped one over the power line right where it plugs into the wall, and another right before it reaches the RCBS Chargemaster. I immediately noticed greater stability in the zero of my scale. The zero does not wander hardly at all at this point, and when it does it is by a mere 1/10th of a grain, which is the rated accuracy of the scale in the first place!
Wrapping up RCBS Chargemaster Modifications
These simple mods have reduced the throw times and increased the accuracy on my RCBS Chargemaster to almost 100% where before the mods I would get overthrows approximately 30-40% of the time. If I was to load 100 rounds of rifle ammunition it might take me 130-140 actual charges dispensed before I had 100 of them at the charge weight I wanted. I recently loaded 300 rounds of 6.5 Creedmoor for the 2014 Sniper’s Hide Cup using my RCBS Chargemaster and if I had three charges that I tossed and reweighed that was a lot these days. With these mods I get excellent accuracy from the RCBS Chargemaster scale and as a result my time sitting at the reloading bench is much more efficient. Less time at the bench equals more time on the range! Go give this a try and see what you think!
Update on 6/8/16
After trying some of the Chargemaster reducing inserts from David Moore, I have to recommend these over the straw mod moving forward. It’s a much more elegant solution to the same problem and it takes almost no fiddling to get it running. Just open the package, install the sleeve, double check your speed settings, and you’re done! They function the same way, by reducing the amount of powder that can progress down the tube at any given time. I recommend getting the option accuracy sleeve that further reduces the tube aperture even below what the brass insert achieves. For $18 shipped, you can’t go wrong. For ordering information on these, see the Chargemaster Reducing Inserts article!