Measuring the velocity of airgun

[Suyash]

Hello everyone
I want to measure the velocity of my air rifle but I don't have any way to do so. Chrony connect is not working with my device. I don't have a chronograph too.
There are many ‘ Unconventional ’ methods to measure velocity for example if the pellet penetrates X cans of coca cola then velocity is . Or penetrating A number of newspaper means that the velocity is B. I don't know much about the topic nor Google seems to help. Probably many IFGns can tell details
Of course I know that velocity is not everything but it is still a major factor in long range shooting.
So can anyone help me with the measuring of velocity?
Suyash

[bennedose]

Try these threads
http://indiansforguns.com/viewtopic.php ... ty#p203424
http://indiansforguns.com/viewtopic.php ... ty#p183526

[Basu]

This is a very nice alternate to get average FPS.
The purity of the sound sample matters most , which means there should not be any echo..the phone should be wrapped with soft cloth or towel.
10 yds is good enough.
I did my first FPS checking with this only and the sound sample was read by Harsha.
It gives average velocity but not muzzle velocity.
Muzzle velocity is always higher than average velocity.

Basu

[brihacharan]

VELOCITY
What kind of velocity are we talking about….
Muzzle ?
Transitional ?
Terminal ?
Also each of these will vary with the weight & shape of the pellet…..
So in which velocity should one be interested in????
Velocity will matter if one were to consider it at the time of hunting, because it correlates with the amount of energy delivered at a particular distance for an effective kill…
So as thumb rule ideal velocities are:
0.117 > 700 / 750fps
0.22 > 600 / 650fps
At these velocities the AR will perform smoothly with good accuracy!!!
Briha

[Suyash]

Briha Ji
I just want to know the velocity of my At at around 5ft ~ with an ordinary 13gr pellets.
Can someone tell me the ‘can rule ’(it was applicable for airsoft at least!)
I really DON'T HAVE ANY IDEA about the velocity of the AR . I'm not in search of the exact velocity of the rifle. I just need a Rough estimate of the fps

[AnandNair]

Suyash...Chrony connect is the best bet. make sure you have a good mobile phone with sensitive mics (iphone, sony etc)
See this video.

or read this post for using audacity
http://www.indiansforguns.com/viewtopic.php?f=2&t=23134

[bennedose]

Briha Ji
I just want to know the velocity of my At at around 5ft ~ with an ordinary 13gr pellets.
Can someone tell me the ‘can rule ’(it was applicable for airsoft at least!)
I really DON'T HAVE ANY IDEA about the velocity of the AR . I'm not in search of the exact velocity of the rifle. I just need a Rough estimate of the fps

Please record a sound sample of 3-4 shots at an accurately measured distance - preferably 10 yards or 10 meters and send it to me and Basu and we will both independently do it for you or tell you that the sound sample is not good enough. If the distance is too short the sound of hitting the target and the air rifle vibration sounds are continuous and calculation can go awry. Remember that the sound of a springer is a prolonged sss-bang-twannng that lasts well after the pellet has left the muzzle.

[Suyash]

Thanks benne , I'll send a sample tomorrow

[Suyash]

Here are two samples with OVER TIGHT gamo(they were only available at the movement)
According to the chrony connect
A=10 m
B=1 m
C= 1.2 m

I'm not sure if you need them.

[Suyash]

Oh sorry. It says'The extension mp3 is not allowed.'

[Suyash]

Can any one tell me how to attach the file
Or benne can you pm me your email address (if you want) so that I can send the audio sample.
Suyash

[Suyash]

At last!! Chrony connect worked ! I connected a Mic to my phone and used balloons as target. The velocityI got was 550 fps
(without tuning).

[Basu]

It is suggested to make the target like round saw cutting blade or 1" thick wooden piece.
The above target will generate soundwaves immediately upon hit.
I am afraid , in case of balloon , it may be a tad late.
If the sound of the gun is high then one needs to put mike further down to allow it to capture clear waveforms.

Basu

[Suyash]

Thanks basu
I measured the velocity by a plastic bottle also and there was no difference.543 fps by balloon and 550 fps by bottle.
But .....will bottle also produce 'double sound' (it pierces both ends of bottle)
I'm not sure.
Regards!!
Suyash

[Suyash]

I've got another question. What kind of velocity is given by chrony connect? Is it muzzle velocity or velocity when the pellet hits the target?
Regards
Suyash