TRX-925 Precision Reloading Scale

Introducing the TRX-925 Precision Reloading Scale by Creedmoor Sports

I have been an avid user of digital scales since I began my reloading journey. It stems from a poor experience that I had with a Lee Safety Powder Scale. I found the thing impossible to use. Inexpensive digital scales were around that cost just a bit more than the miserable option that Lee Precision offered and so I quickly returned the “analog” in favor of the digital. I have never looked back.

As I went from a hobby reloader to a professional one, I have had the chance to use many different digital scales on the market. Those which were offered by Hornady and RCBS are the most notable, however, for a long time I used the venerable A&D FX120i which has become the standby for precision reloaders. Each scale had its strengths and weaknesses but for the most part, none of them were really much to write home about.

When I came to Creedmoor, one of the very first projects I was asked to take part in was the development of a new reloading scale for the precision-oriented reloader. From the get-go, I began to make a list of the things I liked and the things I disliked about all of the other reloading scales on the market. Here are the things I came up with.

  1. Calibration wieghts are not often marked as to the level of precision, and look pretty rough.
  2. The calibration range is often well above the range I’ll actually be using, for example a 10 gram calibration weight weighs 154.32gn, and a 50 gram wieght weighs 771.61gn. If I am loading precision loads for 6.5 Creedmoor and my charge weight is only 30ish grains, that’s way below my first calibration point.
  3. Typical reloading scales are accurate to the +/-0.2gn, and repurposed labs scales like the A&D FX120i were precise to +/-.02gn. Most if not all quality measurements systems should be 10 times more accurate then the least significant digit, so if I care to measure to .1gn then the scale should measure to .01gn.
  4. Powder pans were often a bit small for loading bigger cartridges that require 100gn or more powder.
  5. Powder pans are often set up for people with more petite hands then mine.
  6. Draft shields are a pain to work around sometimes.
Due to the precision of these weights, they ship in their own storage containers. This keeps the dust and dirt off the weight which helps maintain it’s precision.

A Scale is Only as Good as Its Calibration

The handloader usually is pretty ill-informed when it comes to using the proper Class of weight to calibrate the scale. So when the manual calls for calibration the handloader typically will take one of the cheap old weights that came with another less precise scale and will use that to perform the calibration. Not knowing that calibration weight is nowhere near precise enough to calibrate the scale to the level of precision expected of it.

Secondly, calibration is often an afterthought. Handloaders are not calibrating their scales often enough. It should be done every time we sit at the bench, and honestly, if we are doing an all-day marathon session, the calibration should be done every few hours. It is not the fault of the handloader, it is more that we as an industry or as a hobby have not taught “Best Practices”. So as part of the development of this scale, we looked to change that.

We set the scale up to calibrate using three points of reference. A 2 gram (30.86gn), a 10 gram (154.32gn), and a 50-gram (771.61gn) weight. This ensures that the scale is properly calibrated and you have a calibration point close to what your actual working range is. Including high-quality weights, was also simple addition. We looked at the proper weight class needed to calibrate to the level of precision we were after and we selected those weights. F-1 Class weights are accurate out to .0001 grams, which is 10 times more precise than the scale is capable of reading.

When turning on the scale, you will notice that the scale will immediately prompt you to calibrate it. Right off the bat, you can do a quick calibration, and be off to the races. The calibration can be skipped if you wait about 30 seconds, or if you press and hold the Tare button. However, we strongly recommend you get in the habit of following through with the calibration every time the scale has been turned on. This is something everyone can benefit from regardless of the scale you are using if it’s an FX120i or an inexpensive reloading scale.

Hard to Get Excited About A Powder Pan

It might be hard to get excited about a powder pan, so here’s a glamour shot

We designed our own powder pan, again, fairly straightforward. I drew up several variations on a common theme, printed them out on a 3D printer and we put them to use. We figure selected the design that worked the best. For most powders, this pan will hold over 200 grains, which covers pretty much anything up to and including 50 BMG.

We did make sure the pan had a nice slick finish to it that both prevented the static build-up, and made it look good. We added a hole in the handle if you wanted to hand it up on your pegboard, we know it’s not much, but we also know sometimes it is the little things that get appreciated.

Birthed and Raised in Grains, not Grams

The real challenge of this project was to get the precision right. There is a reason why most, if not all reloading scales are accurate to the +/-.2gn, and to +/-.02gn. That is because the scales are not really reading in Grains. They weigh everything in Grams, and then they convert the measurement to grains. 1 Gram is equal to 15.432 Grains, so that is not a very clean conversion. In fact, usually, you are stuck having to round up or round down in the least significant digit. Thus the scale is only able to measure out to +/-.2 accurately. Scales that move incrementally in .1 typically are fudging the number to give the illusion that they are more accurate than they are.

The reason scales do this is pretty simple. Outside of the United States, the world runs on Grams. It’s a unit of the metric system, and that is how most everything is programmed. Most if not all reloading scales started life as a laboratory scale, which got repackaged and rebranded and called a Reloading Scale without much of a change to the way the scale reads or thinks. In order to get around this, we had to change the programming of the scale to measure things not in grams, but in grains. Thereby eliminating any source of error that might be introduced by converting and then rounding the answer.

There is a downside to this approach. Since the scale speaks Grains, whenever we need to measure in Grams, the conversion means we now create a rounding issue when measuring in Grams. This gives the appearance of the scale “hesitating” or being “stuck” on a number. The chart on the right shows where you may see this hesitation. This is a result of the scale rounding internally, and the unit of Grain is a much smaller unit so it takes more grains to make a gram. In the United States, we typically do things exclusively in Grains when it comes to Reloading. So it makes sense to have a scale that is the most accurate to the Grain, not the Gram.

There are instances when I do use Grams in reloading. This is when I measure case volume. It is a handy trick in the metric system. 1 cubic centimeter of water, is equal to 1 gram. Thus if I place an empty piece of brass and tare out the scale, I can then take that case fill it full of water and then place it back on the scale. The difference in weight in Grams is the exact equivalent of volume in cubic centimeters. If these measurements are only accurate to the hundredth (.01) of a gram, I personally can live with that.

Blocking the Draft

Once we had the native units of measure figured out. We had knocked out most of the items on my list of “Must Haves”. The last thing that nearly universally bothers me about scales is the draft shield. Draft shields are a necessary evil. If you reload in a room with fans or a blowing AC, or maybe you are just a heavy breather. The scales we use in reloading are sensitive enough to pick up that air movement and it will result in unexpected “bumps” and shifts in measurements.

The draft shield on this scale is a necessary evil, we had to include it because we know some people will need it, but we all hate to use it. The bonus is, this shield is really easy to modify and if you break it or decide later you want to do something different, you can order a replacement

A draft shield helps to create dead air space around the weighing platform. However, we are constantly moving that powder pan, and we are likely going to have some kind of trickle resting over the pan. Most of the draft shields we came across were a pain to work with, and tricky to modify. The shield we chose, was a compromise, we wanted something inexpensive enough that people would not be shy to modify, but at the same time do its job if it was needed.

Truth be told, we’ve actually found the scale works pretty darn well without the shield in place. At least in the areas where we were loading which did not have a lot of air movement. We know it’s best practice to always use these scales with a draft shield in place, but we also know that practically every reloader we know, does not use a draft shield because they get in the way. This is a long way to say, use it, modify it, or toss it. It’s up to you, we do stock replacements if you’d like to order another draft shield.

Somethings You Might Notice

Calibration Weights in Grams not Grains

One of the things pointed out to us was that the calibration weights are in Grams, but we make a bit deal that the scale reads in Grains. All I can say is “You got us.”

No really though, it can be a bit confusing. The reason the calibration weights are in Grams is that that is really the only calibration weight out there with the appropriate level of precision. Grain is a peculiar unit of measure that is a holdover of a bygone era. Only a very few industries use it. So calibration weights rarely are found in Grains. When calibrating it is important to start with a precisely known weight. In our case, we use the F-1 Class weights which are accurate out to four decimal places or roughly .0001 grams.

(Weight Classification is a topic on its own, but note tolerances are in the Microgram range with the appropriate tolerance dependent on the weight itself.)

During Calibration the scale knows to expect weights weighing 30.865 grains (2 Grams), 154.324 grains (10 grams), and 771.618 grains (50 Grams). Even though weights are in Grams and the Scale asks for the Gram Weight, it reads everything and calibrates everything in grains.

The RS 232 Jack

If you are looking for an cable here’s an option offered at Amazon.com. Click on the picture to be taken there.

This scale includes an RS232 jack. It’s not just cosmetic, it is fully functional and ready for you to use. I am a sucker for data collection, and I like to be able to port data from the scale into my laptop. If I am measuring a bunch of bullets, or I am weight a bunch of charges, I like that data to auto-populate an excel table. We do not include the cable with the scale, but there are several on the market that you can use.

The user manual in the scale goes over the information on how to utilize the RS232 jack. It works great and I have been using it for several months now with no issue.

Giving you Options

We appreciate that is the little things that often make the difference between a good experience and a great experience. One of the things I insisted on was a long cord for the AC/DC adapter. Because I have had to set up shop with limited power options and limited space. The bane of electronics is short cords. So we spec’d out a longer cord for use with this scale to help alleviate the issue.

How does it do what it does?

When it comes to precision scales on the market there are two primary types of load cells (the thing that does the weighing). Magnetic Resoritive Force (MRF), and Strain Gauge. Traditionally when it comes to quality precision reloading scales that weigh on the milligram level, MRF scales have been the norm. MRF base scales have gained a reputation for being more stable, and less sensitive to drafts. They also tend to react quicker than traditional strain gauge scales. The downside of these types of load cells is the price, they are more expensive to make.

Strain gauge baseload cells are the old-timers on the market. Pretty much every precision scale that is in the sub $600 category uses a strain gauge to measure weight. They do so very precisely, and at this point, they are inexpensive. Much of the criticism of strain gauges do not come from the gauge itself, but rather the electronics and algorithms that read the scale and drive the readouts.

When it comes to precision, which other than speed, is the only metric that you and I should care about, strain gauge and MRF-based scales may be equally as precise out to the milligram, or in our case the hundredth of a grain. Scales that require a higher level of precision do benefit from the increased sensitivity that MRF-based scales may offer but it is not needed for our purposes.

Scale drift and other phenomena that have traditionally plagued older scales have been overcome by better electronics and better programming. That is not to say you cannot make this scale drift if you tried, but that is true of any electronic scale including those that use an MRF load cell.

Keeping things Warmed Up

When you power up the scale for the first time, it is best practice to let that scale sit and warm-up for 30 minutes before using it. That is because all electronics give off a little bit of heat, and heat leads to thermal expansion. We are dealing with very small changes in voltages and the minuscule deformation of materials to measure weight. Thus any expansion due to heat must be allowed to happen before we put the scale in use. So when plugging in for the first time, turn it on and then go grab a cup of Joe, or do something else for a little bit. The scale will ask you to calibrate it, but just let it time out on the calibration, we can calibrate it when we get back.

You will find many laboratories do not shut their scales off, they leave them running 24/7 so they do not need to perform this “warm-up”. You do not need to do that with this scale. We set this up so that the vital systems are always powered on. Switching off the scale will turn off the display, which is the power hog. The rest of the electronics remain on and will be kept “warmed up” and ready to use.

This is not like the old vacuum tube days where the heat is so great that the unit will actually feel warm to the touch. The heat is minuscule. Less than a few hundredths of a degree in most cases. It is enough to affect measurements if the unit has not reached “Steady State”. The additional power draw of the LCD and backlight will create a bit more heat, but the distance is great enough from the real sensitive components that it does not create an issue.

The Wrap Up

The TRX-925 Scale, its is a scale we develop specifically from the ground up for precision reloaders.

This is the project I have been working on the longest during my tenure at Creedmoor Sports. It took a lot of testing and time to get things just right. It was important to me that we were able to deliver a quality product, that met my requirements and preferences all while coming in at a price point that was affordable to most guys serious about reloading.

I believe we have achieved that. I am would love to hear your thoughts on it, and if you pick one up, get your feedback. You can purchase the scale exclusively at Creedmoor Sports, the link is here. If you do order it, be sure to put something like “Say Hi to Jay for me”, it’s always fun to hear from guys and gals who visit my page and then order something at Creedmoor.