What is a .22 smooth bore?

A .22 smooth bore is a small caliber weapon designed or modified to fire pellet shots rather than solid round ammunition. This effectively transforms the firearm into a shotgun-style weapon. This barrel format is usually used to eradicate small pest animals.

The typical .22 weapon has a rifled barrel with grooves cut into its internal diameter to provide the bullet greater stability in flight and thus improved accuracy. This rifling is detrimental to any shot ammunition used. Using shot shells allows the shooter to have a wider spread, as several pellets are fired at once. This gives an improved chance to hit the target.