RCBS ChargeMaster Tips

Trouble-Shooting the RCBS Charge-Master

TECH UPDATE for the RCBS ChargeMaster. In a few short months the RCBS ChargeMaster has become the top-selling digital dispenser on the market. Most people using the RCBS ChargeMaster digital powder dispenser have been very happy with the unit. However, we've heard some reports that, on completing a dispensing cycle, the display shows the load to be the correct target weight, when in fact the unit is off by a one or two tenths of a grain. Since the read-out appears "dead-on", the user doesn't know he has a high or low charge. This is why we advise all ChargeMaster owners to initially check their charge weights with a precision scale of known accuracy. If the unit does not meet spec, RCBS will replace it during the warranty period. However, keep in mind that the unit is rated ± 0.1 grain, which means you can't expect it to deliver the EXACT charge (to the tenth) every time--it may be a tenth high or a tenth low, for a spread of 0.2 grains. A recent ChargeMaster evaluation we've done, with charges checked with a Denver Instruments laboratory scale, did show the unit to be within ± 0.1 grain 95% of the time with H4350, and, with most powders, it delivered the exact charge (to the tenth) over 2/3 of the time.

Still there are things that can improve the unit's consistency. Here are some helpful hints, from Chargemaster owners:

1) Make sure the unit is perfectly level front to rear. Some ChargeMasters, particularly the early-production units, are sensitive to front/rear leveling.

2) Don't leave the power cord coiled up in a loop; this can cause a magnetic field that can affect read-outs.

3) Use the hinged door that covers the dispensing tray. This will eliminate drafts.

4) IMPORTANT--after dispensing a load, pick up the plastic powder cup, swish it gently to distribute the kernels evenly, and place it back on the load cell. This "double-checks" the weight and will catch the vast majority of over-charges.

5) There is a high speed/low speed transition point at 25.0 grains of powder--if your load is right near this point you'll see some fluctuation. You can call RCBS and they can tell you how to modify the high speed/low speed parameters.

6) RCBS can also tell you how to re-program the unit to slow the speed right at the end of the dispensing cycle. This has resulted in greater consistency for some users, who report fewer cases of charges "missing the mark."

7) RCBS now ships the unit with a metal pan that is a bit heavier than the original plastic powder pan. Again, this seems to work a bit better.

8) Use the factory-supplied check weights to test for calibration with each session; this only takes a few seconds.

9) Use a good surge suppressor, or better yet, plug the ChargeMaster into a line conditioner that provides "clean", correct voltage. A few users told us all their problems disappeared when they plugged the power cord into a line conditioner or UPS (Uninterruptible Power Supply).