Shooter Operation Manual for Shooter


Overview & Requirements

Shooter is a highly accurate and easy to use ballistics calculator for Android™ that is arguably the best mobile ballistics application available today. Shooter is developed by Sean Kennedy and Berger Bullet's ballistician and world-class shooting champion Bryan Litz. Shooter is only available for purchase in the Android Market at this time.

After you first purchase and install Shooter, the general steps you take to get a calculation are:

  1. Add a firearm by creating a Firearm Profile
  2. Add your ammo by creating an Ammo Profile underneath the Firearm Profile you just made
  3. Select that piece of ammo you just added and you can then enter in current conditions and target data
  4. Get your trajectory in a table, graph or in a "Solution Screen" which gives you large and easy to see correction values and options to change distance, wind, wind direction, lead and lead direction all very quickly for when in the field and sudden changes to any of these variables change suddenly (such as a fleeting Coyote).


NOT Required

Firearm Profiles

Shooter was designed to save all of the data that never changes (firearm and ammo inputs) into profiles so that you don't have to enter this information each time you want to get a calculation. After you add a Firearm Profile or an Ammo Profile, it is saved to your device so that each time you open Shooter you can simply select the gun and piece of ammo you're shooting and be on your way to getting a trajectory calculation.

Adding a Firearm

To add a firearm, open up Shooter and touch the "Add Firearm" button at the bottom of the screen. You will be brought to a screen with several inputs to enter:

Name - This is an arbitrary name that you'd like to use to identify this firearm. This is the name that will be shown on the first screen of Shooter (e.g. 308 Winchester).

Twist Rate - This is the twist rate of your barrel. If you have a 1:10" twist, put 10 here. If you have a 1:11.25" twist, put 11.25 here. This is an optional input and is only needed if you intend to calculate spin drift which is covered later in the manual. If you don't know this or don't want to calculate spin drift, just leave it blank.

Twist Direction - This is the direction of the twist in your barrel (rifling). Most rifles have a right twist, but the option is there to choose left if you have it. This is only needed if you enter a Twist Rate.

Sight Height - This is the height from the centerline of your bore to the center of your sight. To measure this accurately on guns with a mounted scope, measure the diameter (that is, from side to side, not all the way around) of the barrel just ahead of the scope's bell and divide that number by 2. Now measure the diameter of the scope bell itself and divide that number by 2. Now measure the gap between the bottom of the scope bell and your barrel. Now add these 3 numbers together to get your sight height. It should be somewhere around 1-3".

Sight Offset - The lateral offset of the sight to the centerline of the barrel. Positive offsets are to the right and negative are left.

Lead Unit - This is the angular unit you'd prefer to use for lead. Lead is for moving targets. In the shot data input screen, you can specify a moving speed and direction of the target to calculate lead-hold.

Elevation Unit - The angular unit you'd prefer to use for elevation (up/down) adjustments. Look at your scope's adjustment turrets. They should be labled at the top or on the side with what unit they're using or look in your scope's manual. The most common is probably MOA (Minutes of Angle), but Mils and IPHY are also popular. If you're not familiar with these units, a quick Google search will give you loads of information.

Windage Unit - Like the Elevation Unit, except for windage (left/right) adjustments.

Elevation Turret Grad - This is the amount of adjustment per-click of your elevation turret. This too should be labled on your turret or available in your scope's manual.

Windage Turret Grad - Same as Elevation Turret Grad, except for your windage turret. This is very likely the same unit as the elevation's turret.

Elevation Correction - This is used to correct for scope turret clicks that aren't quite what they say they are. If you've come to realize your .25MOA per-click scope is actually .23MOA per-click then you'd put a correction factor of 1.08695652 (.25/.23) because you actually need to adjust more as you aren't quite getting a full quarter MOA per click. So say your elevation solution for a 1000yd shot is 28MOA and you have the correction factor of 1.08695652. Shooter will multiply 28 by 1.08695652 to give you 30.4MOA. So even though the real solution is 28, you'd dial 30.4MOA because your scope only adjusts .23MOA rather than .25MOA per-click. An asterisk (*) will be placed next to the angular unit in the Solution and Trajectory Table screens when using these inputs to denote that the given value is corrected and not the actual calculated correction. Inaccurate click adjustments are more common than you may think. Don't take this for granted. To effectively disable this feature, leave the input set to 1.0

Wind Correction - Same as Elevation Correction, except for the windage.

Once the inputs are added, simply touch the "Add" button to save this firearm profile. You will be brought back to the main screen where you will see your firearm added. You can then touch it once to be brought to the ammo profiles you've added for that firearm. Ammo Profiles are covered below.

Editing or Deleting a Firearm

To edit or delete a Firearm Profile, simply touch and hold the profile for a couple seconds and a menu will pop-up giving you the option to Edit or Delete. If you choose Edit, you will be brought to a screen that looks just like the Add Firearm screen with all of the inputs filled in with the firearm's data. Make your changes and touch "Update". If you originally chose Delete, a confirmation pop-up will ask you if you're sure. Touch Yes to remove the profile (which will also remove all the Ammo Profiles that you added for that firearm).

Ammo Profiles & Bullet Library

To get to to the screen to manage your Ammo Profiles, you first must add a firearm as explained above. Once you do this, touch the firearm profile when you first open Shooter and you'll be brought to the screen showing all your ammo profiles added for that firearm profile and the option to add new ammo profiles.

Adding an Ammo Profile

There are 2 ways to add an ammo profile:

  1. Touch the "Bullet Library" button if you want to select from several hundred bullets and most if not all of the bullet-related inputs of the ammo profile creation screen will be auto-populated for you. It's important to note that the Bullet Library is only there for your convenience. It does not need to exist. It just saves you time from having to go look up the bullet's information. After opening up the Bullet Library, you will be presented with a list of bullet manufacturers. Next you will see a screen of various bullet diameters (calibers). Next you will see a list of bullets (bullet weight and model name) from the chosen manufacturer and diameter. Next you will be brought to the "Add Ammo" screen with bullet data pre-filled (inputs are explained below). If your bullet was not in the library, simply add it yourself using the 2nd option (Add Ammo button).

  2. Touch the "Add Ammo" button if the Bullet Library does not have your bullet. You will enter in each piece of data by hand this way (which is still a very short process that you only have to do once).

Name - This is an arbitrary name that you'd like to use to identify this piece of ammunition. This is the name that will be shown on the ammo profile list that you will see after selecting your firearm profile from the first screen of Shooter. If you used the Bullet Library, this will be pre-filled with manufactur, diameter, and bullet model. You are free to change this to whatever you like.

Bullet Diameter - This is the diameter of your bullet in inches. The bullet diameter is not always exactly the same as the name of your cartridge. For example, the .223 Remington is actually .224 diameter. 6mm Remington is .243. 300 Winchester Magnum is .308. Remember to put the decimal (i.e. for .308, don't put "308" put ".308")

Bullet Weight - The weight of your bullet in grains.

Bullet Length - This is the total length of your bullet (not the loaded cartridge). This is an optional input and is only required if you intend to calculate spin drift in which case you will also need to enter your barrel's twist rate back in the firearm profile.

Atmosphere Std. - This is the atmospheric standard (ICAO = International Civil Aviation Organization, ASM = Army Standard Metro) that your bullet manufacturer referenced their ballistic coeffecient measurements to. This won't greatly affect your trajectory calculations if wrong. Berger, Nosler and Lapua all use ICAO. Sierra, Barnes, Hornady and Winchester use ASM. You'd probably have to call and ask the manufacturer if you're shooting another brand. Again, it won't affect the results too much so that may not be worth your time.

Muzzle Velocity - This is the velocity of your bullet when immediately leaving your barrel. It is highly recommended to test this using a chronograph. This input is very important to get right. If you don't have access to a chronograph, put in your best guess from a reloading manual or from the manufacturer of your ammo and tweak it until your trajectory calculations match up with your real-world shooting. Of course, this should only be done if you're sure your other variables such as atmosphere and target distance are in fact accurate.

MV Variation - This is an optional input, but if you input this field, you also need to input the Powder Temp field for it to be of use. You can specify the amount of variation of Muzzle Velocity per degree of temperature change of your powder. This is something advanced shooters probably know after collecting this data shooting under several different temperatures. They may see that they chronographed avg 2850fps @ 55deg and 2855fps @ 57deg and 2860fps @ 59deg. So they could enter 2.5fps here. Temperature has varying effects on each kind of powder and it's not always perfectly linear so this option is just a "better than nothing" approach.

Powder Temp - This is an optional input and should only be entered if you also entered an MV Variation. This is the base powder temperature and should coincide with your Muzzle Velocity. So as in the example in the "MV Variation" field description above, you'd put 55deg here and 2850fps in your "Muzzle Velocity" field (or you could be 57deg here and 2855fps in Muzzle Velocity, doesn't matter). Now when you run a calculation using this ammo profile, there will be an option to enter current Powder Temp. If you were to specify say 65deg for powder temp, Shooter will automatially raise your MV to 2875fps.

Drag Model - This is the drag model of your ballistic coefficient(s) (BC). Most manufacturers are going to give you a G1 ballistic coefficient and they should specify that. If you're using a long range boat tail bullet, it's actually better to use a G7 BC as the G7 model more accurately plots the trajectory of those bullets, but that doesn't mean you can enter a G1 BC then select G7 and expect to get a better calculation. You must enter G7 BC(s) if you choose G7 and you must enter G1 BC(s) if you choose G1 here. Some manufacturers will give you both a G1 BC and a G7 BC. In this case, it's probably a boattail bullet and you should prefer the G7 BC. For more information about these drag models and ballistic coefficients, I highly recommend Bryan Litz' book Applied Ballistics for Long Range Shooting. You can also find a wealth of information using Google. The bottom line here is you choose whichever drag model your BC values are for which is specified by the manufacturer.

Coef. & Min Velocity - Here you enter your bullet's ballistic coefficient(s) and the minimum velocity for that BC. If you have only 1 BC to enter, just put 0 for the Min Velocity. You can enter multiple BCs for the different velocity ranges of the bullet. Sierra is an example manufacturer that provides multiple G1 BCs for their bullets. For example, the .308 168gr HPBT MatchKing has these BCs and velocity ranges: .462 @ 2600 fps and above; .447 between 2600 and 2100 fps; .424 between 2100 and 1600 fps; .405 @ 1600 fps and below. In this case, you'd enter the following into Shooter for Coef./Min Velocity: .462/2600; .447/2100; .424/1600; .405/0. If you chose your bullet from the Bullet Library, this information will already be filled in and you don't need to touch it.

Zero Range - This is the range to the target that you zeroed your scope at.

Zero Height - This is how high/low you are at your zero range. Say you zeroed @ 100yards and 1" high -- you'd put 1 here. If you zeroed 1" low, put -1 here. If you zeroed dead-on, put 0.

Zero Offset - This is how far left/right you are at your zero range from your point of aim.

Zero Atmosphere - If you zero past 100yards, it's necessary to enable this feature and input your atmospheric conditions. By doing this, Shooter will automatically correct your zero when shooting in different conditions. So if you originally zero @ 500ft altitude and then go hunting with that rifle/ammo @ 10,000ft altitude, your zero point will be off (how much it will be off depends on how far your zero range was) and Shooter will account for this.

Pressure Input Type - This is for specifying how you want to input your current pressure. There is a "?" button right next to this input which explains each option.

Altitude - Your altitude at time of zero. This field will be disabled if you chose "Station" for Pressure Input Type.

Temperature - Temperature at time of zero.

Rel. Humidity - Relative Humidity at time of zero.

Pressure - Pressure at time of zero. This will be disabled if you chose "By altitude" for Pressure Input Type. If you chose "By altitude and corrected SLP" then you need to enter the barometric pressure here. If you chose "Station" then you need to enter the station (absolute) pressure here.

Notes - This is an arbitrary field where you can note down any extra details about this piece of ammo.

Editing, Duplicating or Deleting an Ammo Profile

To edit, duplicate or delete an ammo profile, simply touch and hold the profile and a menu will pop-up giving you these options. If you choose Edit, you will be brought to the same screen as the "Add Ammo" with all the ammo's data filled in. Make your changes and touch "Update". If you originally chose Duplicate, a new "Add Ammo" screen will come up with all that ammo's data filled in which allows you to easily add another piece of ammunition that is similar. Make the necessary changes to the inputs and touch "Add". If you originally chose Delete, a confirmation pop-up will ask you if you're sure. Touch Yes to remove the profile.



Distance - Enter the distance to your target or if you plan to get a table output, just put it whatever distance you want to calculate out to. You can touch the "Calc" button to the right of this input to bring up a dialog to estimate the distance to your target by entering the target's actual size and the size of the target as measured in your reticle.

Look Angle - This is the angle to the target from the perspective of your bore. If you're shooting 30deg up-hill, you'd put 30 here. If you're shooting 30deg down-hill, you'd put -30. If the target is straight in front of you, this would be set to 0. You can touch the "Get" button next to this input which will bring up a dialog that allows you to accurately measure your look angle using your device (note: this requires that your device has an Accelerometer). It's pretty straightforward to see how this measurement works. If you hold your device in one hand in the natural way and then rotate the device downward and upward by moving only your wrist, you'll see the reading get higher as you rotate the top of the device upward and lower and into negative values as you rotate the top of the device downward. The most accurate way to measure Look Angle using this tool is to:

  1. Place the device right on top of your barrel (obviously, make sure you're barrel isn't very hot).
  2. Get your rifle situated and in-line with your target.
  3. Touch the "Start Timer" button and after 5 seconds, it will automatically take a snapshot of the reading, close the dialog, and populate the Look Angle field with the read value. If you prefer, you can just touch the "Hold" button rather than "Start Timer" to grab the currently read value immediately.

Lead Speed - This is the speed your target is travelling.

Lead Angle - The angle of the target's direction with the line of sight. A 90deg angle is a target moving perpendicular to the line of sight.

Atmospheric Conditions

There are 2 ways to input atmospheric conditions. The default which is by entering some combination of altitude/humidity/temp/pressure and by "Density Altitude". If you prefer to use Density Altitude, you must enable this option in the Preferences.

Location & Density - In the grey colored bar at the top of the Atmospheric Conditions inputs, you'll see these two values. "Location" will be populated when using the "Auto Atmosphere" feature (see Preferences) or when manually pulling values by touching your device's Menu button and choosing the "Station Atmosphere" option. The "Density" value updates as you change atmospheric inputs to show the corresponding air density. This is particularily useful if you are comparing Shooter's calculations to some other calculator so you can be sure that the air density for both calculators are the same before making the comparison.

Density Altitude - If you have enabled Density Altitude in Preferences, then pressure input type, altitude, humidity and pressure inputs will be gone and you will see Density Altitude and Temperature instead. If you've enabled Density Altitude then I assume you know what it is and how to use it. If you don't know, then just don't use it and skip this. The reason you must enter Temperature as well (even though the Density Altitude value incorporates temperature already) is because the actual Temperature must be known for Shooter to calculate the speed of sound which is important for calculating an accurate trajectory.

Pressure is Absolute - When this is checked, you are stating the the pressure you input above it is Station pressure. When unchecked, you are stating the pressure being inputted is Barometric pressure.

Altitude - Your current altitude. This field will be disabled if you chose "Station" for Pressure Input Type because Station pressure is absolute and altitude is irrelevant.

Temperature - Your current temperature.

Rel. Humidity - Your current Relative Humidity.

Wind - You can enter your wind directly, or you can touch the wind input box itself and bring up a wind dial screen.

Using GPS and the Internet to pull in current atmospheric conditions

Shooter offers the ability to populate your atmospheric inputs by grabbing your current location via the GPS in your device and then downloading current conditions from a nearby weather station using the Internet. To use this feature, you must obviously have a device that has GPS capability and is connected to either WiFi or a data connection through your phone's service provider.

There are 2 ways to pull this data in:

  1. Auto: By enabling the "Auto Atmosphere" in the Preferences. When this is enabled, Shooter will attempt to get a GPS fix and download weather data as soon as you open up the shot data input screen. Once it gets this data, the atmosphere fields will be populated for you and the "Location" will be updated to show where it pulled weather data from.
  2. Manual: You can touch the Menu button on your device and choose the "Station Atmosphere" option. This does the exact same thing as "Auto Atmosphere", it's just invoked manually. You can use this even when "Auto Atmosphere" is enabled to force it to re-pull data.

Using your Bluetooth-enabled Kestrel to load atmospheric conditions

If you have a Bluetooth-enabled Kestrel Weather Meter along with a Bluetooth-enabled device running at least version 2.0 of Android, you can pair them and load the readings from your Kestrel directly into the atmospheric inputs of Shooter. If you're running a pre-Android 3.0 device, then this feature requires you to download the free plugin "Shooter BT Plugin for Kestrel" from the Google Play Store.

Directions if using plugin

In the environment screen, touch the Menu button on your device and choose the "Kestrel Atmosphere" option. A dialog will appear asking if you want to download the plugin from the Market. Choose Yes and download and install the app just like any other application from the Market. This plugin is not an app you can find and launch from the application launcher of Android -- it's only accessible from within Shooter as explained below.

Once you have the plugin installed, follow these steps to get your Kestrel talking to Shooter:

  1. Turn on your Kestrel and go into the settings and then "Bluetooth". Set Bluetooth to "On" and then go to "Info" and note down the PIN it shows.
  2. On your Android device, go to Settings (not settings in Shooter, settings of Android itself) and then Wireless & Networks. Make sure Bluetooth is enabled and then go to Bluetooth Settings. Touch the "Scan for devices" option and wait for your Kestrel device to appear under the "Bluetooth devices" section. Once it does, touch that device and a dialog will appear asking for the PIN. Type in the PIN that you noted down in step 1 from your Kestrel. It should now say, "Paired but not connected". Once you do this, you never have to do this again. Android will remember your Kestrel device.
  3. Now open up Shooter and choose your firearm and ammo and then once in the Shot Data input screen, touch Menu and go to "Kestrel Atmosphere". You will be brought to a screen showing your paired devices. Touch the device that is your Kestrel and you will be brought to a screen of the current atmosphere readings from your Kestrel (it can take a couple second to start showing the values). Touch the "Load" button at the bottom to get dropped back to the shot data input screen and those values populated into your atmospheric input fields.

When you're using the plugin, you can touch the Menu button on your device and go to Preferences. Here you can set the Default Device. Choose your Kestrel device from that list and the next time you open the plugin, it won't ask you to choose your device again and take you right to the current readings screen. This saves a little time.

Directions if using built-in
  1. On your device, go to your Bluetooth settings and turn Bluetooth on.
  2. Turn on your Kestrel and make sure Bluetooth is enabled on it.
  3. In the Bluetooth settings of you device, you should see your Kestrel device listed after a short period of time. Select it and enter the PIN (the PIN can be found under the Bluetooth settings of your Kestrel device).
  4. Open Shooter, then open the Settings by selecting Menu->Settings.
  5. Scroll down to "Kestrel (Bluetooth)" and select it. You should see a list of paired BT devices. Select the Kestrel device.
  6. You may now back out of Settings and continue on to selecting a firearm/ammo profile, then once at the Environment screen, go to Menu->Atmosphere from Kestrel.

Powder Temp

If you have specified a MV Variation and Powder Temp in the ammo profile you're using, you will see a Powder Temp section. Here you can specify your powder temperature to have Shooter auto-adjust the Muzzle Velocity based on your variation. The "Temperature" field here will auto-update with whatever you populate into the Temperature field under the "Atmospheric Conditions" effectively making the default powder temp 'ambient'. If you want to put in some custom powder temperature that's different from the outside temperature, just change the value and it will stop auto-updating with atmosphere temperature changes.

Spin Drift

If you've selected a firearm profile that has a Twist Rate defined and selected an ammo profile that has a Bullet Length defined, you will see a "Spin Drift" section in the shot data input screen. To enable this calculation, simply toggle the On/Off button to ON. This isn't really necessary for short-range targets. Explaining exactly what Gyroscopic Drift is and how it works is beyond the scope of this operation manual. Please see Bryan Litz' article on spin drift here:

Coriolis Effect

To enable Coriolis Effect calculation, simply toggle the On/Off button to ON and enter the following inputs:

Latitude - This is your current latitude position on Earth. Do not try and enter Longitude here as well, Latitude is all that is needed. Your GPS-enabled device can populate this field for you by enabling "Automatic Latitude" within the Preferences.

Azimuth - This is the direction to your target clockwise from north. So if you're target is directly north, you'd put 0deg here. If the target was directly to the right of North, you'd put 90deg here (directly left 270deg). You can use the "Get" button directly to the right of the Azimuth input to use your device to find the Azimuth. Once you start up the Azimuth aquisition dialog, it's a good idea to move your device up, down, side to side and in circles to calibrate the compass. Now point the top of the device directly at your target and let it stabilize. Touch "Hold" to close the dialog and load the value into the input.

For information about the Coriolis Effect and how it works, please see Bryan Litz' article here:

Solution Screen

This section is coming soon.

Trajectory Table & Graphs

This section is coming soon.


Preferences allow you to customize several of the features available in Shooter to your liking. You can access the Preferences by touching the Preferences button at the bottom right of the screen when you first open Shooter or by touching the Menu button on your device and choosing the Preferences option which is also on the first screen of Shooter (Firearm Profile screen). Most of these options are self-explanatory.

Operation Mode - You can choose Simple or Advanced. The default is Advanced which gives you access to all of the inputs and features of Shooter. If you choose Simple, several "advanced" options such as powder temperature/muzzle velocity variation, coriolis effect, spin drift and zero atmosphere will be disabled and hidden. If you're just starting out and don't understand these options, it's recommended to just set this to Simple.

Color Scheme - Choose "Day" for a light colored theme or "Night" for dark

Firearm Sorting Order - This is how you want your firearm profile list to be arranged.

Ammo Sorting Order - This is how you want your ammo profile lists to be arranged.

Distance Unit - This is the preferred unit for all distance measurements (Yards or Meters).

Atmosphere Unit - This is the unit to use for atmospheric values (Imperial or Metric).

Other Unit - This is the unit to use for all other types of inputs such as Bullet Length, Zero Height, Sight Height, etc (Imperial or Metric).

Wind Angle Unit - This is how you want to enter your wind readings. You can choose Degrees (0-360 or -90-90) or Clock for 1-12 O'Clock.

Lead Angle Unit - Similar to the Wind Angle Unit, but for the Lead Angle input (direction target is moving).

Mildot Spec - If you have a scope which uses Mils, you can specify what mildot spec it uses. 1 USMC Mil = 3.438 MOA; 1 Army Mil = 3.375 MOA. This may be in your scope's manual or you could contact the manufacturer and ask them.

Use Density Altitude - If you prefer to use Density Altitude to input your atmospheric conditions rather than entering altitude/pressure/humidity, enable this option. If you don't know what this is, don't use it -- it's just another way of entering your atmospheric conditions.

Automatic Latitude - If your device has GPS, you can enable this option to automatically populate the "Latitude" field for the Coriolis Effect inputs in the Shot Data input screen.

Automatic Atmosphere - If your device has GPS and access to the internet, you can enable this option to auto-populate your atmosphere conditions using data from a nearby weather station.

Disable Wind Population - If you enabled Automatic Atmosphere, you can enable this option to prevent it from populating the Wind Speed field so you can enter that by hand as the wind is very likely different at your exact location.

Save Distance - Enable this to save the last entered distance so that the next time you go to the Shot Data input screen the distance will be pre-filled with whatever distance your last calculation was.

Save Atmosphere - Enable this to save the last entered atmospheric conditions so that the next time you go to the Shot Data input screen the atmospheric conditions will be pre-filled with whatever data your last calculation had.

Always Enable Spin Drift - Enable this option to always enable spin drift calculations by default. This of course is only applicable if the firearm and ammo profile have the necessary inputs required to make such a calculation (that is, your firearm profile has a Twist Rate defined and your ammo profile has a Bullet Length defined).

Always Enable Coriolis - Enable this option to always enable coriolis effect calculations by default.

HUD Distance Step Size - This is the amount to increment/decrement the "Distance" input within the Solution screen with each +/- tap.

Hide Linear Path/Drift - If you don't care to see the linear path/drift (drop/drift in inches/cm) within the trajectory table, enable this option.

Show Clicks - If you enabled Hide Linear Path/Drift, you can choose to replace the linear path/drift columns with click-values instead by enabling this option.

Range Step Size - This is the target distance step size of each row in the trajectory table. Some shooters may want to see trajectory data every 5 yards others only every 50 yards.

Sorting Order - You can choose to see from top to bottom 0 yards out to your calculated distance (Ascending) or from your calculated distance down to 0 yards (Descending).

Web Sync

This section is coming soon.