If I have a .22 inch dia bore by 19 inches long, and a projectile of 14 grains, a pressure of 800 PSI What....

Question

If I have a .22 inch dia bore by 19 inches long, and a projectile weight of 14 grains, and a constant pressure of 800 PSI. What would the muzzle velocity be for this projectile?

Specifically, I want to take the barrel off an old .22 LR rifle, and convert it for use with .22 caliber pellets using CO2 as a propellant. I'm not sure what the friction costs would be for this, but my calculations seemed to be between a .200 and .300 coefficient of friction (please correct me if I'm wrong, I'm sure of how the coefficient of friction is noted).

If you could please post the formula(s) that you used as well it would be appreciated.

So far I've got .038 sq in. with a pressure of 800 psi = 30 lbs of force. But that's where I'm stuck. I'm not sure how to calculate the acceleration when time is not known. I know distance (19 inches), but I don't know time.

Thanks!

Answer 1

Force*distance = work = kinetic energy

However, barrel drag and coefficient of drag are only remotely related. Barrel drag is all about edge contact with the barrel, while coefficient of drag has to do with shape and air resistance.