How to chrono your gun with a PC
Posted: Wed Sep 30, 2009 11:05 pm
How to chrono your gun with a PC
What you will need.
1- measuring tape
2- computer with mic to record your shots
3- Download Audacity (Open Source sound recording utility) found free here http://audacity.sourceforge.net/latest/audacity-win/audacity-win-1.2.6 .exe
How it works:
FPS feet per second.Here we will find out the fps by measuring the time it takes for a bb to travel from the moment you fire a shot, to the moment that the bb hit the target. And knowing the distance between the two.
1. Set up a firing area with a hard target such as a piece of metal to shoot at.
2. With the measuring tape measure how far away the target is you intend to shoot. Mine was 12 feet
3. Position the microphone to pick up both the sound of a shot being fired, and the bb hitting the target.
4. Open audacity and hit record on your pc. After firing the shot hit stop.
Calculating the FPS:
All we are going to do at this point is to find the time between these 2 peaks, of these 2 sounds.
To do this all you need to do is select the space between the two waves with the mouse, and on the bottom it will show the time between the two waves.
[img width=500 height=361]http://www.firebred.com/chrono.jpg[/img]
FPS = Distance/Time
I used a distance of 12 feet and got a time of .0348299 seconds
FPS = 12 feet /.0348299 seconds = 344.5315663 FPS or 344 fps.
I tested this on a gun that was chronographed at DS3 and came up with close to the same numbers. At DS3 it chronographed at 358 fps with .25s tonight at 344 fps.
What you will need.
1- measuring tape
2- computer with mic to record your shots
3- Download Audacity (Open Source sound recording utility) found free here http://audacity.sourceforge.net/latest/audacity-win/audacity-win-1.2.6 .exe
How it works:
FPS feet per second.Here we will find out the fps by measuring the time it takes for a bb to travel from the moment you fire a shot, to the moment that the bb hit the target. And knowing the distance between the two.
1. Set up a firing area with a hard target such as a piece of metal to shoot at.
2. With the measuring tape measure how far away the target is you intend to shoot. Mine was 12 feet
3. Position the microphone to pick up both the sound of a shot being fired, and the bb hitting the target.
4. Open audacity and hit record on your pc. After firing the shot hit stop.
Calculating the FPS:
All we are going to do at this point is to find the time between these 2 peaks, of these 2 sounds.
To do this all you need to do is select the space between the two waves with the mouse, and on the bottom it will show the time between the two waves.
[img width=500 height=361]http://www.firebred.com/chrono.jpg[/img]
FPS = Distance/Time
I used a distance of 12 feet and got a time of .0348299 seconds
FPS = 12 feet /.0348299 seconds = 344.5315663 FPS or 344 fps.
I tested this on a gun that was chronographed at DS3 and came up with close to the same numbers. At DS3 it chronographed at 358 fps with .25s tonight at 344 fps.