handgun vs rifle velocity & energy .22

Question
I have a friend that says the speed or velocity is the same using the equivalent bullet given on a handgun and rifle,he claims the foot pounds are no different, I say there is a vast difference on impact of foot pounds from a rifle that has a 22 ' barrel versus a 5' barrel on a handgun.

Is there a better explanation.

Thanks

Mike

Answer
You are more right, but not always, the longer the barrel when dealing with pistols (6 inch or smaller) verses rifles 16 inches or longer, there is a big different in foot pounds and velocity.  However, there is a point where too long of a barrel starts to do the opposite.  That would depend on the round, powder and other factors.

A 10 inch barrel shooting the same bullet will have much more velocity than a 5 inch barrel.  The theory is when a bullet explodes (the powder ignites) the explosive force is pushing and building all the way down the barrel, so the second the bullet leaves the barrel all the force that was contained in the barrel is now escaping everywhere and is no longer pushing against the bullet.  So the longer you keep that explosive force pushing the bullet it builds up speed and velocity.

Of course if you had a barrel a quarter of a mile long, the bullet may never reach the end of the barrel since the explosive force is losing pressure as it pushes the bullet.  That is the extreme but for the most part, if you can hold a rifle and the barrel length is a few feet or less, most all bullets will have more velocity out of a rifle (longer barrel) then from a pistol (shorter barrel).  

In fact some ammo manufactures give velocity ratings from a 6 inch gun since it will be faster than if they used a 2 inch gun.  If you ever see someone shooting with a velocity gauge, you can prove this yourself by shooting the same round from different size barrels and you will see the velocity changes.