how the gun is work?
The cartridge contains the projectile, the explosive and the primer. The firing pin in the weapon strikes the primer, igniting the explosive. The only way for the hot gas produced to escape is through the barrel, so it pushes the projectile down the barrel and out the muzzle.
The velocity of the projectile will vary, depending on its weight, the length of the weapon's barrel, the type of explosive used and the quantity of explosive used.
thank you for the correction sytasyn_syn.
My new reply....
How does a gun work?
What happens is you pull a trigger. It releases a firing pin, which in turn impacts with a primer cap. Contained within the primer cap is a small explosive, which in turn sets off a larger explosive, which is mainly due to smokeless powder. That will send the bullet on its way through the barrel of a weapon.