There's a calculator on an American Airgun website for working out muzle energy:
http://www.pyramydair.com/site/articles/formulas/
I use it all the time and it's very handy.
There's a calculator on an American Airgun website for working out muzle energy:
http://www.pyramydair.com/site/articles/formulas/
I use it all the time and it's very handy.