First Impression: Desert Tech’s TRASOL Ballistic App

First Impression: Desert Tech’s TRASOL Ballistic App

I am a big believer in ballistics applications. In 2019, at the US National Matches at Camp Perry, Ohio, I spent the better part of an hour taking wind readings with my Kestrel windmeter containing Applied Ballistics software. I watched a brisk wind condition oscillating between three and seven minutes of angle of wind correction before shooting the 600-yard stage of the President’s Hundred Match. The wind fluttered up and down in a 90 second cycle. The course of fire was to shoot ten rounds with no sighters at the midrange target on Viale Range in a time limit of ten minutes.

The week before the P100 match, I had monitored the Kestrel over four days shooting the Civilian Marksmanship Program’s Cup Match series. I was shooting an AR-15 Scoped Service Rifle, a specific variation of this widely used rifle design specifically configured for across the course competition.

CMP Cup Matches are shot on electronic targets with sighter shots. I was carefully taking notes of how changes in air temperature and pressure during the day were slightly changing the elevation of my impacts on the targets at the various distances I would be shooting in the main event, the U.S. National Matches, the next week.

The research paid off. I managed to shoot all ten shots of the 600-stage of the P100 into the 10-ring cleaning the target, scoring the maximum 100 out of 100 points, in just over 4 and ½ minutes in perfect harmony with the wind oscillation cycle. It was one of less than a dozen “cleans” recorded that day out of around 900 competitors. It was not because I was a better shot than them; I am not nearly so by any stretch of the imagination. It was because I had better ballistics data than most of them in that one specific moment when the shots counted the most.

Data Nerding

When I was asked to have a look at the Desert Tech TRASOL app, I jumped at the chance to get a first impression. As you might guess, I have several ballistics applications installed in my phone and I do use them a lot. I keep libraries of loads I’ve developed for my rifles for purposes from known distance and precision rifle competition to hunting and tactical engagement. I care about all the nerdy details. Velocity, ballistic coefficient, drop versus distance, spin stability, Coriolis, slope angle, density altitude, bullet stability, flight axis alignment, moving target lead, cant angle, and of course, the almighty wind.

All of these are to be found in the TRASOL app. It didn’t take long to stick in my known numbers for the loads I wanted to enter. The app equipment library comes with a .308 Win Example which contains the standard specification for a 175-grain boat tail hollow point round, commonly known as the specification for the U.S. military’s M118-LR ammunition. Using data I already had on my other apps, I quickly added entries for a 155-grain Sierra 2156C bullet .308 Palma competition load; and another for a 77-grain Sierra Match King .223 Remington load that emulates another gold standard military round, the U.S Army’s Mk262 Mod 0/1 5.56x45mm NATO.

I also tried loading random ammunition combinations where I would have to hunt for manufacturer specific bullet diameter, weight, ballistic coefficient and length information. My impression about loading the equipment library is that, if you have the load data already compiled in your notes, it’s quick and easy. If you do have to look things up, there’s room for improvement in the app and its support infrastructure.

My suggestion after my first impression is that I think TRASOL users would benefit by having a bullet data library within the app that is synced and kept up to date automatically as part of the app syncing itself with the user’s account. Luckily it looks like a bullet library is on the way in Trasol, and users will soon be able to look up the data directly from the Trasol data entry screen.


TRASOL’s equipment library, the collection of loadings you create, is synced by each device to Desert Tech’s cloud server. This is a very handy feature if you have multiple devices you use the app on. Create something on your iPad, sync it to your cloud account, then go to your iPhone, start the app and sync it manually. The item you made on the other device will appear. Both devices need to be connected to either the telecom network or to WiFi at the time each is synced. You can build up a list of your favorite gun-load combinations quite quickly. The nuances can be as meticulous as the specs for the different loads in the same gun or the same ammunition in different guns; handy if you shoot the same ammo in both a 16” and 30” barrel.

My first impression wish list of the equipment library may be picky, but I am into my comforts if I can get them.  My wish list begins with the TRASOL not having a list sorting feature. I tend to add load entries randomly as I put firearms through their paces with a chronograph at the sending end and an electronic target that can estimate arrival velocity at the impact end. A nice feature to have would be to allow sorting the equipment display by caliber, bullet weight, B.C. or even alphabetically. It would be even nicer if there was a way to download and upload libraries to a CSV file to maintain larger inventories of load datasets and/or exchange information with other users such as teammates using common load data. These are tools that are common in older P.C. based ballistics and load development applications. Presently, they are not common features in Apple Web Kit based device apps. As an aficionado of external ballistics tools, I admit that I do look for convenience touches in the apps I use regularly.

Head Up Displays

The head up display feature is what particularly excited me about having a look-see at the TRASOL app. I have used many applications, with their versions of heads up displays, including some that take advantage of the sensors built into today’s handheld devices. The TRASOL heads up presentation is particularly nice because it’s the only one I’ve seen that takes advantage of the phone’s camera to pick up the target alignment. This lets the phone’s internal sensors determine slope angle and compass direction for Coriolis, among other things. You can magnify the image up to four times (4X), which is nice.

The key operator ergonomics design point of the TRASOL is that it uses a calculate now button that will take a measurement and freeze that data on the screen. I’ve used other HUD displays that automatically re-calculate elevation correction data based on slope angle. Some do it continuously, which has utility during scene observations. Others recalculate when detecting a significant slope angle change based on a threshold in the settings, which I also find quite usable. TRASOL does not calculate aiming information changes on its own. It waits for the shooter to pick when to make the calculation.

My first impression is that, while I do like the explicit “press this button and do it now” method. I also like moving my rifle around a target and watching the HUD calculate as I aim to get a feel for how close to the edge of needing to hold off or make a click I am. I would suggest adding the option for constant calculation and threshold calculation in the setup menu. It would improve the ability to the TRASOL app to “feel out” the engagement space. That is good stuff for spotters and team leaders working on mapping out a range card efficiently. To me, this would be a good thing.

Advanced Moving Target Measurement

The coolest thing about this app is the automated capture and calculation of leads on moving targets based on sensor data collection. The TRASOL HUD has a button on the lower right with the icon of a person, that kind of reminds me of a portion of those watch out for pedestrian signs on a highway, but I digress. Aiming the HUD camera at the target, pressing that button, following the target for a bit, and pressing the button again activates the internal accelerometers inside every phone and tablet to measure the angle rate change of the device during the observation. That match turns into a accurate empirical measurement of the targets speed, and then ballistically into how much to lead the target. It’s the same math that’s inside a Continuously Computed Impact Point (CCIP) or Pipper in a fighter jet’s HUD. It works. It’s totally cool. My first impression is that the full version of this app is a must have for this feature alone.

My primary ask for this feature is that it would be nice if there was a moving target measurement mode where you push once to start the process, have the device wait a built in delay time while you line up the indicator on the target, then just ask the operator to keep the marker on the target for a settable amount of observation time somewhere better 5 to 10 seconds.  After that, automatically stop the observation and present the lead estimate.  I think this ergonomics versus pressing a button to start and then pressing it again to stop would be rather lovely.


I had to use either known distances or my non-integrated range finder to get target distances with the app. There is a slider bar at the bottom of the HUD to set the range manually. My first impression here is that I did not have the tools to really do this aspect of the app justice. I do not have a Terrapin-X rangefinder that automatically feeds range into to the app via a Bluetooth connection. Nor a gun that can reach out to where one can really appreciate what it means. The biggest blaster I’ve got is a .284 Winchester; that’s a round that only goes to about a third of the distance I’d like to have a look-see at figuring out how this app can really drive as a reach out to the “King of Two Miles” type distances. And for the record, heck yeah, I would like to try it sometime. That would be fun.


Is this app worth buying and adding to an already crowded iPhone or iPad bristling with other ballistics apps, training apps, terrain maps with GPS positioning and property boundary overlays, clinometers, weather, on and on? For the advanced device sensor technology exploitation features Desert Tech has integrated into TRASOL, the answer is a definite yes.

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