At the range, do you feel like you’re guessing where your rifle will hit past 100 yards? When shooting longer, do you sometimes think it’ll take 12 clicks to spin your scope up to target, when in fact it takes eight? Do you find yourself “walking in” impacts, half a box at a time?
You friend, have a ballistics problem. Lucky enough, there’s an app for that.
Software ballistic problem solvers, which use sophisticated algorithms to compute bullet trajectory, come pre-installed in a wide range of shooting electronics, from wind meters to rangefinders and wrist watches. Or you can also download them direct to your Android or Apple smartphone. There are many of these apps available. They all take the same basic rifle, ammunition, target, and environmental data, crunch the numbers, and tell you where to hold. Here’s how they work:
Screengrabs courtesy of Ballistic Advanced Edition. Other apps may look different, but will all ask you for the same data.
Setting the Ballistic Coefficient
The first step is selecting the projectile. In this app, you need to click, “Ballistic Coefficient.”
Ballistic coefficient is a mathematical value representing a bullets ability to overcome air-resistance in flight. Think of it like “streamlined-ness” whereas the higher the value, the more streamlined and the less air resistance the bullet encounters in flight.
Thanks to physics, narrower, heavier bullets always have a higher B.C. than fatter, lighter bullets.
Entering Ammo Data
At the top of the next screen in the Ballistic App, you can select “Bullets,” which uses a traditional G1 model of B.C.
Or you can select “Loads,” which allows you to make the same selection based on name brand factory ammunition, or “Litz,” which computes B.C. on the model developed by Berger ballistician Bryan Litz.
For classic calibers like .308 or .30-06, select use a G1 model by selecting “Loads.”
For modern rounds, like 6.5 Creedmoor, select “Litz” to use the G7 model.
In a different app, the wording may be different but the takeaway is the same: older calibers = G1, modern precision calibers = G7.
For this example, we’ll select “Litz” and a .243 caliber Hornady 108gr ELD Match bullet—my go-to 6mm Creedmoor load.
Most phone-based ballistic calculators will auto-fill the Muzzle Velocity based on the ammo manufacturers data. This will work, but will only get you so far.
Beg, borrow, or steal a chronograph and test your rifle and ammo if you hope to take long-range shooting seriously. Here we’ll input the velocity computed for my Bergara HMR when shooting Hornady’s 108-grainers.
This was determined with a LabRadar unit, so the chronograph distance is “1 foot.”
Enter Scope Data – Sight Height, Line of Sight Angle
After data from your ammo and rifle is inputted, it’s time to log your scope.
First, enter the distance you zero’d the rifle at, which should be the default value of 100 yards.
Next, input your Sight Height. This is the distance in inches from the centerline of your barrel to the centerline of your scope tube. There are a couple ways to do this. Quick and dirty: get a tape measure and eyeball it.
If that doesn’t feel right, get a pair of calipers and measure the diameter of your rifle bolt, then the diameter of your scope tube. Add those numbers up and divide by two. Next, measure the distance from the top of the bolt to the bottom of the scope tube. Add that to your first figure, and you have scope height. Confused? Sinclair has a good explainer here.
When that’s settled, click LOS Angle, which stands for Line of Sight. This calculates the angle of the shot, whether uphill or downhill. Only do this if and when you’re lined up on target and ready to fire.
In this app, LOS Angle brings up a level, which you can place on your rifle barrel to auto-compute and capture the measurement.
Enter Environmental Data
Next, you need to input environmental data, namely the conditions when the rifle was zero’d and the conditions while shooting right now.
In both cases, this app and others can use your phone’s GPS to find you, and pull up a local weather report. Make sure “Pressure is Absolute” is not selected when you first locate your weather info, by pressing the little blue beacon in the righthand corner.
Next, configure how you want your sighting data delivered. For the sake of this example, I selected 1,000 yards as our max range, to be displayed in 25-yard increments. The scope on this rifle is MOA and the MOA value is the true 1.047.
Not all scope manufacturers dial their turrets to this true MOA figure. Vortex, for example, uses an MOA value of 1.0. If you don’t know the MOA value of your optic work some Google-Fu or call the manufacturer. If your optic is not MOA, change it over to mRad for MILS.
The mRad default in most scopes and ballistic calculators is every click equals .1 mRads. If you’re not sure of yours, look at your scope turrets. They will be marked.
If you’re shooting past 600 yards, enable Spin Drift and Coriolis Effect calculations. For Spin Drift, you may need to know your bullet length, which can be found online or ball-parked.
Most modern bullets like the Creedmoors run between 1.2 and 1.4 inches. The rate of twist on this rifle is 1:8.
Now you’re ready to see results. Select “Ballistics Chart” to see a graph of your bullet’s trajectory.
Select “Calculate Trajectory” to get your come-ups.
In this example, I need to spin up the elevation turret on my scope 18.2 MOA to connect with this rifle and load, in these conditions, at 1,000 yards.
More Long Range Ballistics Gear
Some people have a mortal dislike of doing anything but making calls on their phone. I don’t blame them. Smartphones have turned many of us into distracted, hunched-over bores. Fear not, fellow troglodyte. You don’t need the latest update of iO-whocares to solve ballistic problems.
These three shooting gadgets process the same level of data as the app above, with the added benefits of wind metering, range finding, and wrist-worn computing.
You won’t find a precision shooting match anywhere in the world where the contestants aren’t swinging these expensive little beasts around to better read the wind.
It can hold 30 rifle/bullet profiles that it can instantly provide elevation adjustments for at pretty much any distance you’ll find a target. It also provides windage holds by measuring wind speed and target direction. It also measures real-time barometric pressure changes and automatically adjusts accordingly.
The Applied Ballistics engine is baked into this top-tier rangefinder from SIG, so when you ping a distant target it doesn’t just tell you the range, but the correct holdover to hit it.
It’s ideal for fast target acquisition and engagement, either during competition or for long-range hunting.
This wrist-watch sized GPS with built-in ballistic calculator has been deployed with the U.S. military for some time, because it does two things very well: provides basic navigation; accurately computes where to hold to hit a long-way-off target.
Think of it like a sandbox special. The “target card” feature will show you data for multiple targets, which is great for jumping around various distances quickly at the range.