What Wind Meters Does The Hornady Ballistics App Link Up With

Ever wondered what ballistic app the best shooters use? Here are the answers! This article covers the ballistic apps the top precision rifle shooters are running to calculate their firing solutions for first-round hits at long range. The data is based on a recent survey I conducted of the top-ranked shooters across the country in both the Precision Rifle Series (PRS) and National Rifle League (NRL). (Learn more about the PRS & NRL). This is a very unique data set, because it includes a wide sample size (170+ shooters) who also represent the leading experts in the field. (View all the What The Pros Use articles) This is the first year I've asked about ballistic calculators, phone apps, and drag models, so it was exciting to see what these pros trust to give them accurate trajectory prediction.

A decade ago, most serious shooters agreed the only way to know what your real adjustment should be to hit a target at long range was to carefully collecting DOPE (Data On Previous Engagements) from the field. You'd try to shoot to as many distances as possible and record what adjustment was required to center a hit at each distance. Then you'd combine all that data into a printed dope card (like the one shown), and use that in the future to infer adjustments for new distances you need to engage. The accuracy of this approach was thought to be better than the theoretical data generated by ballistics engines at that time. The problem with that approach is those static dope cards were based on how the bullet flew in a particular set of atmospheric conditions, and the corrections might be different if conditions changed or you traveled. For example, if the data was gathered when it was 90° the adjustment might be off by a few clicks if you were firing in 40° weather, and the same would be true if your elevation or other factors changed as well. So while this was the proven approach for the longest time, it took a lot of time and ammo to generate and wasn't accurate in different atmospheric conditions.

Thanks to huge advances in technology and pioneering research in external ballistics, we've largely closed the gap between theoretical data generated by ballistics engines and hits in the field. I'll never forget going to one of my first rifle matches with a brand new rifle that I got just a couple days before. I hadn't even shot it past 100 yards! The match had targets from 300 to 800 yards, and a few veteran shooters literally laughed out loud when I told them I hadn't shot the rifle past 100 yards and was running 100% theoretical/unproven dope. But I'd carefully measured my muzzle velocity when I zeroed at 100 yards, and I used Bryan Litz's G7 BC for my bullet to create my firing solution – and I ended up hitting 38 targets in a row before my first miss. I only dropped 2 targets over the whole match, and finished 2nd overall … and both misses were more me than my ballistic solution.

Clearly there are ballistic engines out there that can be trusted when supplied with good inputs. I'm not suggesting you blindly trust them and not put them to the test in the field. That was dumb! But the old days of having to shoot at every range you might encounter and use that to create charts seems to be in the past. I do still verify the adjustments my ballistic engine is giving me at a few distances, and may have to "true" the trajectory slightly to center my hits, but it's rare that I'm off target if I'm careful to use good inputs and a good ballistic calculator.

Tip: In order to generate an accurate ballistic solution you must measure the actual muzzle velocity from your rifle, and find the most accurate BC for your bullet. Remember, garbage in – garbage out. Most serious shooters measure their muzzle velocity over 10+ shots using a LabRadar or MagnetoSpeed to find their average velocity. They also ignore the BC printed on the box of bullets and instead plug in a BC based on live-fire experiments conducted by Bryan Litz (found in this book). If you have solid numbers for those two inputs and use a quality ballistic engine, the output it generates should be very close to your actual hits in the field.

Most Popular Devices Used To Calculate Ballistics

Let's start by looking at what kind of devices the top shooters are using to calculate their ballistics. Keep in mind that often times in major precision rifle matches just 1 or 2 misses can be what separates 1st place from 5th place! These guys are fiercely competitive, and have an extremely high standard for the accuracy they expect in their firing solution.

You can see most of these pros trust one device above all the others: The Kestrel Ballistics Weather Meter with Applied Ballistics. 76% of shooters were running a Kestrel to calculate their adjustments and wind holds in matches where every shot counts. A Kestrel Weather Meter allows you to measure the wind speed at your location, which can help you establish a baseline for your wind call. The Kestrel also acts as a handheld weather station that gathers onsite atmospherics. It features sensors for temperature, humidity, and pressure, along with a compass, and will use all those inputs to customize your firing solution. This device runs a ballistic engine created by the team over at Applied Ballistics, which is regarded by many as one of the most accurate in the industry. The engine has a lot of advanced features, like accounting for secondary effects such as spin drift, aerodynamic jump, and Coriolis Effect. It allows you to use a few different drag models, including either G1 or G7 BC, or something called a Custom Drag Model (CDM), which I'll dive into more detail on in an upcoming post. The Applied Ballistics engine also features several ways to fine-tune or "true" your ballistic model like drop scale factor and accounting for temperature sensitivity of the powder in your ammo by automatically inferring the muzzle velocity based on inputs you provide for various temperatures. There is even a model that features LiNK, which allows it to communicate wirelessly via Bluetooth you're your phone, rangefinders, and other devices. Frankly, a Kestrel Weather Meter combined with an Applied Ballistics engine is a one-stop-shop that packs all the features you might ever need in a ballistic solver. Street price on the baseline model (without LiNK) is $600, and the model with LiNK is $700.

While I was working on this content, I ran across a great article in Precision Rifle Shooter magazine written by Sam Statser with the title, "You Can Do It!" The article discussed Dan Jarecke's journey from being a new competitor just two years ago to finishing 6^th overall in the PRS last season, and it shares Dan's tips on how to get started in precision shooting. It's one of the best articles I've read in a while, and you can likely still find that magazine on newsstands. In that article, Dan emphasizes the importance of a good ballistic calculator, explaining that "many great shooters still use a firing solution app or solver from their phone, but one of the first 'big buys' that Jarecke recommends outside of your rifle and optic is a stand-alone ballistics calculator. The Kestrel is without peer in this department." The Kestrel is an expensive piece of gear, but Dan says, "For many reasons, the money you will spend on a Kestrel wind meter with the Applied Ballistics engine is well-worth it." I couldn't agree more, Dan.

Phone Apps For Ballistics

22% of the shooters said they use a phone app to calculate their ballistics. There are certainly some good phone apps out there. When it comes to phone apps, one critical thing to consider is how it determines atmospheric conditions. This was a point that Dan Jarecke also thought was important enough to mention in his tips:

"If you start shooting in the early morning at a match, the temperature could be 70 degrees (Fahrenheit) and up to 95 by the afternoon. If a shooter does not recognize the change in density altitude over the course of the day, their firing solution won't be accurate, and they may start to blame their gun, their ammunition or their optic for their sudden lack of ability to successfully engage targets," explains Jarecke. "Since precision rifle is a game of removing variables, atmospheric data should not be a guess. It should be 100-percent, real-time accurate."

Some phone apps pull the current atmospheric conditions from the nearest weather station data it can access (hopefully it's not 100+ miles away), provided your phone has data service when you need it (which can be a problem at some ranges). There are also some devices you can pair with your phone to capture a complete on-site atmospheric profile, including temperature, pressure, relative humidity, and density altitude. If you're able to gather on-site atmospherics, your solution has the potential to be just as accurate as the Kestrel. In fact, Kestrel makes one of the options for gathering atmospherics called the Kestrel DROP for $130, which can connect to your phone via Bluetooth and provide real-time data. The most popular option is the WeatherFlow WEATHERmeter for $85, which can also provide real-time, on-site atmospherics to your phone via Bluetooth, plus it can measure the wind speed at your location.

For the 22% of shooters who said they use a phone app to calculate their ballistics, I asked them a follow-up question about which app they used exactly. Here is what they said:

Geoballistics BallisticsARC was the most popular ballistic phone app used by this group of elite shooters, representing 33% of the shooters using phone apps. Geoballistics BallisticsARC is a free app available for iOS and Android devices, and the free version features a bullet library with 2500+ bullets, functionality for truing muzzle velocity, and support for weather hardware integration to gather onsite atmospherics. The app also features a GPS-based "rangefinder" that can provide rough distances to various points on a satellite image. The "premium" version of the app is $15, and allows you to build unlimited rifle profiles, export/save range cards, connect to a Kestrel via LiNK, and a few other things. The feature that allows you to build/save satellite imagery range cards seems like it'd be very handy if you primarily practice from one or two positions on the same range.

Applied Ballistics Mobile app was also very popular, representing 21% of these top shooters using phone apps, including a couple guys who finished in the top 10 in the NRL. This is the same ballistic engine that is used by the Kestrel Elite Weather Meter with Applied Ballistics, which has ALL of the advanced features you might hope a ballistic engine would have. AB Mobile can do all the things I described when talking about the Kestrel above, except you'd need an external device like the WeatherFlow or Kestrel DROP to gather on-site atmospherics. However, it appeared the functionality to pair with an external device was only available on the Android version. A couple useful and unique features in the AB app include bullet comparison graphs, an interactive heads-up display, and a reticle output view to help you visualize where you would need to hold on the reticle to correct for both elevation and wind. The reticle view is a pretty cool idea, although reticle choices are limited. This app is $30 for iOS or Android versions, which does make it the most expensive of this group.

Hornady 4DOF Ballistics app was the 3^rd most popular ballistic app, with a little over 13% of shooters using phone apps choosing to run it. 5 shooters said they used the Hornady app exclusively to calculate ballistics, and there was 1 more that used the Hornady app and the Trasol app. Hornady has become an industry leader through their heavy investment in Research & Development, and they have some bold claims when it comes to their 4DOF (Four Degrees Of Freedom) Ballistic Calculator. They say it "determines trajectory solutions based on projectile Drag Coefficient (not Ballistic Coefficient), combined with exact physical modeling of the projectile and its mass and aerodynamic properties. Additionally, it is the first publicly available calculator that will accurately determine the correct vertical shift a bullet experiences as it encounters a crosswind; referred to as aerodynamic jump." Both Hornady and Applied Ballistics seem to be moving away from calculating trajectories using standard BC's and instead are developing customized drag models recorded by a Doppler radar for each specific bullet, which more closely matches the exact drag of a specific bullet at all speeds and can therefore be used to predict a more accurate trajectory path. I'll touch on that in more depth in an upcoming post, but this Hornady app allows you to use that rich Doppler-derived drag profile for bullets in their "4DOF Bullet Library" … which is still fairly limited at this point, but includes most Hornady bullets that would be used for long range, as well as data for a few bullets from other brands like Berger, Lapua, Nosler, Sierra, and Warner Tool. The Hornady app clearly features an advanced ballistic engine, and it can also be paired with external devices to pull in real-time atmospheric data. I will say that the Hornady app has one of the most polished looks and is more user-friendly than other apps I've used. It's also FREE, and available for both iOS and Android devices. They do have in-app purchases, like a Multi-Heads-Up Display for $1. This app already has a ton of great reviews in the app stores, and I'd only expect its popularity to grow as Hornady adds more bullets to its 4DOF library, especially with all the features you get for the low price of FREE! 😉

Strelok Pro was tied for the 4^th most popular ballistic app, with 13% of shooters running it. There are actually a few versions of this app, including a free version (Strelok), a more advanced version for $5.50 (Strelok+), and then the full-featured version for $12 (Strelok Pro). All of these guys said they were using Strelok Pro, which is available on iOS and Android devices. A couple highlights I noticed about this app was that it also has a reticle view that allows you to visualize what your hold should be if you hold for both elevation and wind corrections, and it features 1460 different reticle designs (view full list)! Surely your's in there! 😉 (I actually noticed my new favorite reticle, the Nightforce Mil-XT, is not in there yet … but it was only released a few months ago, so I bet it is soon.) It also features a bullet database that includes the G7 BC's for 400 bullets. It can also use G1, G7, or custom drag models based on Lapua's Doppler radar data. It seems to account for advanced factors like aerodynamic jump, spin drift, Coriolis effect, etc. It can gather angle of incline with the phone's camera. It can pull atmospheric data from the internet, or the Android version supports connecting to the Kestrel Weather Meter, Kestrel DROP, or Weatherflow WEATHERmeter or WINDmeter. It even has ways to account for powder temperature variance, and truing the trajectory. Honestly, I hadn't personally heard of Strelok before this survey, but after learning more about it, I'm not surprised that so many shooters are using it. Strelok Pro is clearly an extremely full-featured app and ballistic solver.

Ballistic AE is another very popular shooting app, and 10% of these guys running phone apps were using it. It is a very polished and user-friendly app, and claims to be "The #1 Ballistic Calculator" for iOS devices. It isn't available on Android devices. It uses the legendary JBM ballistic engine, which many shooters consider one of the best. This is far more than a basic ballistic calculator. It allows you to configure complex wind scenarios with multiple winds at different ranges. It provides access to a vast library of 5,000+ bullets and factory/military loads. It integrates performance data points from leading manufacturers and military testing, like several G7 military coefficients measured at the Aberdeen Proving Grounds, as well as Bryan Litz's custom BC's and projectile length data. It also allows you to compare up to 8 bullets on the same screen to see performance differences. The advanced Heads-Up Display (HUD) is one of the most quick and user-friendly designs I've seen. AE stands for "Advanced Edition," and that version is $10. The "Standard Edition" is $13, which doesn't seem to make a lot of sense! Ballistic AE offers an in-app purchase that allows you to connect to a Kestrel via LiNK for another $10.

Shooter app was right behind those, with 8% of these top shooters choosing it to calculate their dope. Shooter uses its own custom ballistics solver that supports G1 and G7 drag models. It is fast and accurate, and claims that it's "calculations normally match JBM's numbers within round-off error (0.1″ at 1000 yards)." The engine does allow you to take Coriolis and spin drift into account. It features a library with over 1,300 bullets, including Bryan Litz's measured ballistic coefficients for over 175 popular bullets. One unique feature is that it allows you to use multiple ballistic coefficients for varying velocities in your trajectory, which some bullet manufacturers provide for a more accurate drag profile. It also has features that allow you to account for temperature variance of your powder and automatically adjust the muzzle velocity based on the current temperature. You can load atmospheric data from the internet (i.e. pull from the nearest weather station) or pull it from a Bluetooth-enabled Kestrel device straight into the app. It also allows you to compare trajectory and wind drift for up to 6 loads at once. The Shooter app is $10 and available on iOS or Android devices. I will mention that this is the app that Robert Brantley used to win the King of 2 Miles last year (view What The Top Shooters Used), which included first round hits on targets out to over 3500 yards! Clearly the trajectory predictions it's capable of making are pretty good.

Lastly, one shooter said they sometimes use Trasol, which is a ballistic calculator made by Desert Tech that is available on iOS or Android devices. Here is what Desert Tech says about this ballistic engine: "Utilizing proprietary algorithms, TRASOL is the most accurate ballistics calculator on the planet. No more need to alter manufacturer bullet data to get your hits; we developed new algorithms using Doppler radar data to create the most predictive flight path possible. In live-fire testing of TRASOL's predictions the following results were documented (.338LM ammunition, using manufacturer's published data): within 0.1 MRAD up to 1400 yards, within 0.5 meters up to 1700 yards, within 1.1 meters at 2200 yards." They also claim it's simple and intuitive, and based on the screenshots it seems to be. One of the unique features I noticed was a HUD that uses your phone's camera and onboard sensors and user-friendly drag and drop functionality to input range and wind details. It also allows you to capture both photos and videos to log shots and share them with friends. The iOS app is free, but there is an in-app purchase for access to the full set of features for $25. The Android app is $10. Not sure what's going on there, but that's what I found. There weren't many of these guys using it, but seems like it has some novel features.

Well, that wraps up the apps that these guys are using to calculate their firing solutions in the field. Over the next couple posts, I'll dive into a few other details related to this, including technical things like what kind BC or drag model they're using, as well as try to explain how they actually view the data while they're on the clock. So stay tuned for more!