How did rifling improve the performance of cannon?

Rifling improves the performance of cannons by cutting spiral grooves into the bore, which impart a gyroscopic spin to the projectile as it is fired. This rotation stabilizes the projectile during flight, significantly increasing accuracy compared to smoothbore weapons, which suffered from erratic flight due to the loose fit required for muzzle loading.123

In the mid-19th century, the adoption of rifled small arms by infantry meant that traditional smoothbore field artillery was often outranged, creating an urgent military necessity to adapt rifling to heavy cannons. While the principle was well understood, implementing it in artillery presented technical challenges, such as ensuring the projectile engaged the grooves effectively without compromising the barrel or the loading process. Engineers eventually developed systems using elongated, lead-coated projectiles or shells fitted with soft metal studs that aligned with the rifling grooves, allowing the projectile to grip the barrel's interior and achieve the necessary spin.41