Let's take this calculator for creating custom drag function from bullet dimensions. How we can use calculated drag in Strelok Pro?
Tap this link to see all parameters entered to Bullet Drag Calculator
Create new text file with name "LikeCity_175.snr" and fill it according this picture:
Here is the finished file LikeCity_175.snr
If you have Strelok Pro for Android version 7.2.0 and later you can tap on this file/link and custom drag-function will be imported to Strelok Pro. Use it instead of ballistic coefficient
Open Cartridge screen create new cartridge and enter new cartridge name, bullet length, diameter and weight. Select G7 drag-model and tap multiBC button.
Let's take speed of sound is equal 1,125 ft/s or 343 m/s at 20 °C (68 °F). If you have speed units in feet per second multiply Mach number by 1125 to get speed in fps. If you have speed in meters per second multiply Mach number by 343 to get speed in meters per second
That's it! Now you need to measure your bullet speed at different temperatures and you are ready to shoot!