An English flintlock blunderbuss

A blunderbuss is a muzzle-loading firearm with a flared, trumpet-like barrel. The blunderbuss was in use in the 17th century, and is the weapon most commonly pictured in the arms of the Pilgrims. Flintlock blunderbusses were used by Catherine the Great's forces during foreign wars to expand Russia's territory.

The funnel-shaped barrel is not designed to enhance the ballistics of the weapon, but serves to facilitate loading ammunition into the muzzle. This makes it much easier to refill a blunderbuss with shot (or whatever is available) in situations where this would not normally be possible (say, riding shotgun on a stagecoach speeding down a bumpy road). A blunderbuss can fire multiple balls simultaneously, and generally discharges its entire load at once.

By its nature, the blunderbuss is not a very precise weapon. Although it was sometimes used in a military setting, it was more effective when the goal was not to hit a specific target, but rather any one of multiple targets, such as for crowd control . The blunderbuss has become a byword for inaccurate marksmanship in any field, and the word itself has also come to mean a clumsy or stupid person.