A blunderbuss, was a type of muzzle-loading long arm that included a flared, trumpet-like barrel that was ideal for spreading shot. The blunderbuss was the predecessor of the shotgun, and was often used for crowd control. They were in use during the 17th century, and were commonly pictured in the arms of Pilgrims.
The wide flared muzzle at the end of the barrel were often exaggerated for psychological effects and to aid loading for a moving coach or horse back not to improve the spread.
The myth that a blunderbuss was sometimes loaded using a hand full of whatever hard debris was at hand is true, but they were not standard missiles, as using them makes calculating the weight and bulk of the load difficult. Instead, blunderbusses were more likely to be loaded using a number of pistol or musket balls, or buckshot.