Quote: Changing the powder or charge changes the velocity. That's the action that the rifle is reacting to, if you want to be all Newtonian.
Its part of the formula. The powder charge or gases are moving forwards therefore there must be a corresponding rearward reaction. As for the physics, don't ask me.
-------------------- John aka NitroX
...
Govt get out of our lives NOW!
"I love the smell of cordite in the morning."
"A Sharp spear needs no polish"