FPS-How to determine other way?

[Basu]

Dear all,
To my mind, every airgun lover like to know the power of his gun.Today I did a small experiment with my .22 done 2500 shots with chrokee spring, using 13+ grains pointed head.A 600ml thumsup pet bottle, filled with water set at 15 mtrs,10 mtrs,7 mtrs and 5 mtrs.
Results-at 15 mtrs pellet went through either side as it did not hit water level.At 10 mtrs it pierced one side could not pass through.At 7 mtrs it was the same.At 5 mtrs it pierced both the side across water.
I request those who have cronoed their guns to do the same and share their feedback that at what maximum distance it can pierce both the side and the FPS of their guns. This may help those who do not have access to crono.

Basu

[navneethgopal]

nice experiment yar!
Evn i wanted to know the mv of my gun. If smone here cud relate your experiment with chrono readings it wud be helpful for many like u n me. I relate power of my guns by the number of newspaper sheets it can pierce. My 0.177 ihp pistol does 70 sheets while 0.22 commando 75 does 180 sheets. How abt yours? Do carry out new experiments n some we can have a cost effective simple homemade chrono! I really appreciate ur innovative ideas.good yar! Keep going.

[brihacharan]

Hi Basu,
> Very interesting, however there are a couple of variables one needs to take into consideration to co-relate FPS Vs FPE (velocity Vs power)
1. The thickness of the PET bottle - this may vary from batch to batch - even a few microns would alter the equation.
2. The weight & configuration of the pellet (by configuration I mean Round Head / Pointed / Metal Tipped etc)
> The method adopted by you is only a thumb rule estimation of the equation - any way after going through your experiment I tried it and here are the results - ofcourse these are only indicative.
> My IHP35 0.22cal, tuned & fitted with synthetic seal + Diana imported spring & SS rear guide & top hat, using 14gr Pointed Pellets (International Export) gave chrono readings of an average of 710 fps.
> The shots fired at 7 & 10 metres on 500ml PET Pepsi bottle filled with water passed through end to end. I could not try this at 15 metres for want of an ideal location. May be I'll do it in the near future & keep you guys posted.
> Hence if a weapon can pierce (end to end) a PET bottle filled with water at 7 & 10 metres - then the FPS can be considered as 700 / 710 fps. This as I said is a Thumb Rule estimation - but gives you a ball park idea!
Cheers
Brihacharan

[Basu]

Hi Briha,
thank you so much for your contribution in regard to those who neither have access to crono nor can afford it.
A guesstimation always on the card once one undergoes this exercise.


Basu

[Basu]

Dear Briha,
I tried this again with Both PEPSI and THUMSUP 600 ml pet bottles ,filled with water.In case of PEPSI, my .22 pointed head went through and through at 8.14 mtr(Max distance I had).But in case of THUMSUP it could do at 5 mtr only.
I would request you to do the same exercise with THUMSUP 500ml pet bottle only and post your feedback.

Basu

[hamiclar01]

considering the effect prevailing winds have on pellet path and velocity, would it not be more appropriate of you estimate your mv close to the muzzle, rather than at multiple distances? after all, a chrono would be positioned close to where the bullet exits, to provide muzzle velocity