PACT High Speed Digital Precision Powder Dispenser
Monday, December 30, 2013 (17:52:52)

Posted by Pumpkinslinger

PACT High Speed Digital Precision Powder Dispenser
by Mike Hines (originally written in 2005)

Whenever I make up loads that will be near maximum pressure for hunting, or that require extra precision for matches or varmints, I like to weigh every powder charge. The spherical and flake powders generally meter very well, so all I need to do is throw the charge with my old RCBS powder measure and stick it on the scale to verify the weight. However, I never seemed to have much luck doing that with the extruded powders that I’ve been using in some rifles. Charge weights varied too much around what I wanted. My procedure for those powders has been to throw a charge a little lighter than I want, place it on the scale and trickle the rest of the charge in with a manual trickler. I get good accuracy like that but it’s time consuming. And I’m already pretty slow when loading!

I’ve been using a PACT electronic scale to weigh my powder charges for quite a while. It is just as accurate as my old RCBS beam scale, and it sure is faster and easier to use! The scale has an infrared communications port built into it, but I’d never tried to use it. I knew that there were some electronic powder dispensers around, but my impression was that they were very slow. Then I read about the new PACT “high speed” dispenser that worked with their digital scale using the infrared port. This unit has two speeds. It uses the high speed to dispense most of the charge and then switches to low speed to trickle in the last bit. Midway had the dispenser on sale at the time I started looking. Since I was getting ready to test some more hunting loads I bought one to see if it would speed up my loading process.

When you look into the bottom of the powder hopper on the PACT you’ll see that it has two feeding tubes to get the powder to the scale pan. One is the high speed, high volume feed and the other is the “trickler”. The key pad has the regular numeric keys plus keys for “ENTER”, “RESET”, “CALIBRATE” and “DISPENSE”. There are four LED indicators for “Scale”, “Calibrate”, “Memory” and “Dispense”. The powder hopper holds a pound of powder and has a baffle built in. The use and orientation of the baffle is important to proper operation.

Setting up the dispenser was a breeze. There are only three pages of instructions which I highly recommend that you READ! Part of these is how to activate the scale’s infrared transmitter and establish communication with the dispenser. You have to place the scale under the dispenser to line up the infrared ports on both devices. The “Scale” LED will be on solid when the scale and dispenser are communicating. Make sure you have a pan on the scale before you push any buttons so you won’t make a mess.

The dispenser must then be calibrated for the powder you are using. Apparently there are some “smarts” built into it that constantly adjust to optimize the feed rate. To calibrate you just fill the hopper with the powder you are using and hit the “CALIBRATE” button. One thing I always do, and did here, too, is to tap the hopper with something, a screw driver or wrench, to settle the powder a bit before I start trying to measure. The “Calibrate” LED will blink while the unit runs its routine. The dispenser runs around 150 grains of powder into the pan in spurts for about 2 minutes. The exact amount isn’t important. The dispenser is learning what speed to spit out powder to get to the desired weight as fast as it can. When the calibration is finished the “Calibration” LED will be on solid.

Once the calibration is complete operation is equally easy. Simply punch in the charge weight you want using the numeric key pad and hit the “ENTER” key to store it. Don’t forget to use the decimal point key! The “Memory” LED lights when you have a weight stored. When you are ready to throw a charge you just hit the “DISPENSE” key. The “Dispense” LED will start blinking and the dispenser spits out the requested amount of powder pretty quickly. If the charge comes up short you can press the “DISPENSE” key again to trickle a little more in. The time varies some between charges as the dispenser corrects itself on each cycle. I set the charge weight to 50.0 grains of H4831SC and tried ten cycles. The average time was 25.0 seconds with a high of 34.6 and a low of 16.3.

I loaded twenty .260 Remington cartridges to get used to using the PACT. I noticed that a few charges came up 0.1 grain short. The instructions say that the dispenser tries to never throw an overcharge. However, a couple of times it overshot by up to 0.3 grains. When that happened the next charge would dispense more slowly. It seemed to me that the tuning could be a little too tight, causing it to occasionally overshoot the corrections. I called PACT to ask about that and they said that that was just the way it worked. However, I knew that I wasn’t talking to one of the “high tech” folks there. The dispenser comes with a certificate for a free software upgrade so I might get to use it for this.

To compare the new dispenser with my old method I loaded up some .260 Remington cartridges using H4831SC powder under a Hornady 140 grain SST bullet. The charge weight was around 45 grains. The PACT was set to give me the exact weight. The RCBS thrower was set to throw about 0.5 grain less than the desired charge, according to my usual practice, with the rest of the powder being trickled in by hand. I timed how long it took me to load ten cartridges by each method.

The cases for the comparison were prepped and ready for the powder and bullet. I threw a weighed charge and then seated a bullet before going to the next cartridge. I took my time, as you always should when loading. Using the RCBS and the manual trickler it took me 17.4 minutes to load ten cartridges. Using the dispenser I was able to seat a bullet while it measured the next charge so the time was 10.3 minutes, including one “re-throw” that went over weight. I had to use the “trickle” feature a couple of times to bring the charge up to full weight.

The PACT instructions mention that, for large powder charges, you can throw most of the charge with a manual measure and then use the PACT to finish it up. That method could speed up loading the really big cartridges.

Emptying and cleaning the PACT was a bit more difficult than with the RCBS. Even after you dump the powder back into its original container you need to shake any remaining powder out of the feed tubes. I pulled the powder hopper off to make sure that the tubes and baffle weren’t holding any residual powder. Some compressed air might save some time here. For now I’m using a small paint brush with long bristles to make sure there is no powder left in the dispenser.

I found that I like the convenience of using the dispenser. I’ll admit that the overshooting issue worries me some though. I think what I’ll do for now is to set the dispenser to throw a charge 0.1 grain low then use the “DISPENSE” button to trickle in the last tenth when I need to. Being able to throw a charge in one case while seating a bullet in another sure is a time saver! Since the timed test I’ve loaded some other cartridges using both extruded and spherical powders and was very pleased with the PACT. I don’t know if the dispenser will work with other brands of scales. If you don’t have the electronic scale, PACT or one of its distributors sells a kit with both scale and dispenser included.