Please educate me on how to calculate what a specific projectile (caliber, grain weight, barrel length, etc) would require for air pressure and volume to make said projectile exit the barrel at a given velocity. I've not found this in my searching, and it may be backwards from the norm but so be it. I'd like to see if there's a way to calculate this.
For example, if I had a .300 pellet rifle and I wanted to convert it to .308 by installation of a new barrel, is there a way to calculate whether the gun's existing air volume and cylinder fill pressure would be enough to send the new projectile at a given speed after the conversion? (regardless of hammer, port size, etc) Basically it would be doubling the pellet's grain weight, a % of increase in bore diameter, and to have a velocity (the goal here) around 980fps.
Edited...
For example, if I had a .300 pellet rifle and I wanted to convert it to .308 by installation of a new barrel, is there a way to calculate whether the gun's existing air volume and cylinder fill pressure would be enough to send the new projectile at a given speed after the conversion? (regardless of hammer, port size, etc) Basically it would be doubling the pellet's grain weight, a % of increase in bore diameter, and to have a velocity (the goal here) around 980fps.
Edited...