Bullets spin when shot from a rifle or handgun because of the rifling inside the gun barrel. Rifling consists of spiral grooves cut into the barrel's interior which engage the bullet as it is forced through the barrel. This engagement imparts a rapid spin to the bullet around its longitudinal axis. This spinning stabilizes the bullet in flight through the gyroscopic effect, preventing it from tumbling and maintaining its pointed end forward. The spin balances aerodynamic forces and increases accuracy by conserving angular momentum, which resists external forces trying to change the bullet's orientation. Without this spin, the bullet would tumble, lose speed, power, and accuracy.
In summary:
- Rifling is spiral grooves in the barrel.
- The bullet deforms slightly to fit these grooves and spins as it travels down the barrel.
- The spin stabilizes the bullet and improves flight accuracy through gyroscopic stabilization.
- This spinning effect is critical for the bullet's stable, accurate trajectory.
