Applied Ballistics Toolbox App – Online Guide

The Applied Ballistics Toolbox is a set of tools that shooters can use across multiple applications. It is designed for speed, and ease of use. It does not require an internet connection, so it is off the grid friendly.

Link to app in Google Play: Google Play Link

The following table lists the features of the Kestrel LiNK App and gives a brief explanation of what they are/do.  Greater detail along with directions for how to properly use all the features is given below in the instructional sections of this page.

  1. Application – The AB Toolbox App gives the shooter tools in the field to do very specific calculations and adjustments without the need to remember complex formulas.
  2. Spin DoctorTwist Rate Calculator, with the Complete Custom Library, which tells you if your barrel twist is optimum for the bullet you wish to use, and gives you a corrected BC if your twist rate is not optimum.
  3. Density AltitudeAllows you to calculate DA (Density Altitude) by entering basic information using either Barometric or Station Pressure.
  4. Sight Scale FactorThis tool works in conjunction with our Tall Target Test, and takes the math out of the operation. It is used for getting a turret correction factor, so you know if your turrets are tracking correctly. Here is the link to the Tall Target Test PDF
  5. MIL RangingAllows you to mil targets using the reticle in your scope, has a small library of target sizes for reference.
  6. Chrono Correction – This tool gives the shooter a corrected MV based on the distance between the rifle and chronograph.
  7. Slope Dope – Inclination Angle Correction. Calculates for Uphill/Downhill firing solution corrections.
  8. AB Custom LibraryThis application comes with the full Applied Ballistics Custom Drag Model Library built in.
  9. Quick Reference Animal ChartThis allows the user to have a reference chart based on popular animals for use in MIL Ranging.
  10. Copy Function – You can copy certain functions like SSF, and MV to be pasted in to other apps.
  11. Dark ThemeA dark theme is used to preserve night vision during low/limited light conditions.
  12. Metric SupportData inputs/output can be configured to use Metric units.
  13. Auto ConversionUnits are automatically converted when switching between different units of measure.


Operational Overview
The general flow of the program is designed for quick access, and does not require an internet connection optimizing its use in the field.


Main Menu
This screen gives you access to each of the 6 tools.

NOTE: At any time during the use of the app, you can change units of measure. If you do change units of measure, it automatically does the conversion for you.



Spin Doctor
This allows you to check the SG (Gyroscopic Stability) of your bullet. Not only does it give you a stability factor, it gives you the corrected BC for your SG. For every 0.1 shift in SG you get a 3% +/- change in BC. We take the guess work, and math out of this for you, but also incorporate the Applied Ballistics Library at the same time. Simply pick the bullet from our library, input your data, and it will return you an SG with a corrected BC. Note Altitude can be changed to Pressure if you want to use Station Pressure. Calculate the gyroscopic stability of your bullet based on your bullets: caliber, weight, length, velocity in your specific atmosphere. Spin Doctor answers the question about what bullets will be stable in your rifle. Furthermore, Spin Doctor tells you if a particular bullet is under stabilized, and how much the Ballistic Coefficient (BC) of the bullet may be compromised due to marginal stability. Spin Doctor contains a bullet library which includes bullet: length, weight, caliber, G1 and G7 BC’s. In this way, the Spin Doctor app also functions as a basic BC look up. The bullet/BC library contained in Spin Doctor contains all the live fire measured BC’s that are published by Bryan Litz in: “Ballistic Performance of Rifle Bullets”. The Spin Doctor app works with English and metric units.

  • To select a bullet, simply click at the top where it says “You have not selected a bullet”
  • After you input your parameters, simply click “Calculate” At the bottom.


Density Altitude
This tool allows you to calculate DA (Density Altitude) by simply entering your basic atmospheric data. Aside from being able to input Barometric Pressure, you can also input Station Pressure, and the units of measure are adjustable. Next update will include speed of sound calculated. The Density Altitude (DA) utility calculates DA based on various combinations of environmental data. English and metric units are supported as well as barometric pressure and altitude vs. station pressure. This utility is useful just to see, for example, how much a given temperature or pressure change affects your DA.


Sight Scale Factor
The SSF utility works with MILS and MOA, as well as meters and yards. This tool goes along with our Tall Target Test (URL). Now, you can simply input your Range, which needs to be at a minimum to the tenth of a yard/meter (it is best to measure to the hundredth), you can input your scope adjustment, and your poi shift (to the thousandth of an inch if you want). It will then return the correct (SSF) Sight Scale Factor for you. This will allow you to do a Tall Target Test with multiple points of impact, and calculate each SSF instantly. One of the most common reason shooters miss targets at long range is because scope turrets don’t always track accurately. For example, you might dial 30 MOA but only get 29 MOA from your scope. The Sight Scale Factor (SSF) utility allows you to calculate a scale factor to correct your calculated drop based on your scope error. The way it works is, you conduct a ‘Tall Target Test’ at 100 yards where you measure your Point Of Impact (POI) shift and you input your expected (dialed) POI shift. The calculator determines a SSF that you need to apply in a ballistics program to correct for improperly tracking scopes, putting you on target at long range.

Sight Scale Factor goes along with the Tall Target Test found here: Tall Target Test

Sight Scale Factor has a Copy button, which allows the user to copy your SSF and paste it in to other apps, like AB Mobile, AB Tactical, or LiNK Ballistics.


Mil Ranging
This tool gives you the ability to range targets through your scope. Simply input the Target Size, and the Target Size in Reticle, and it will return the Range to Target. You can change units by simply clicking on the unit itself.

You also have the ability to bring up a reference chart. By clicking on “Target Size” you will bring up a reference chart for Belly to Back on different animals.



Slope Dope
This tool gives you a simple correction for shooting uphill/downhill. While not as complex as the firing solution found in the AB Solvers which accounts for the slowing of the bullet. This tool does give you a simplified firing solution correction for uphill/downhill shooting.



Chronograph Correction
This tool will provide you with a correction MV based on the distance between your chronograph and your rifle. By using the actual recorded velocity, the BC of your bullet, and the Distance to the Chronograph. This tool provides a fast and accurate MV correction for the distance between the rifle and chronograph.

You also have the ability to Copy MV, so that it can be pasted in to our other apps.




  • Android v5.0 or higher.
  • Region and Carrier Limitations: This app is not approved for all regions and/or carriers at this time. Some carriers may choose to block this app due to the nature of its content.
  • No internet connection required
  • Not available on iOS