In firearms, rifling is the helical groove pattern that is machined into the internal (bore) surface of a gun 's barrel, for the purpose of exerting torque and thus imparting a spin to a projectile around its longitudinal axis during shooting. This spin serves to gyroscopically stabilize the projectile by conservation of angular momentum, improving its aerodynamic stability and accuracy over smoothbore designs.
why is rifling present in the bore of the barrel
for the purpose of exerting torque and thus imparting a spin to a projectile around its longitudinal axis during shooting