Wall guns were large caliber smooth-bore muskets that were used in the 17th and 18th centuries by defending forces to break the advance of enemy troops. They were too heavy to be fired from the shoulder and so were usually rested on window ledges or low walls, hence the name. Some of these weapons had multiple barrels which enabled volleys to be fired. The word caliber (American English) or calibre (British English) designates the interior diameter of a tube or the exterior diameter of a wire or rod. ... muskets and bayonets aboard the frigate Grand Turk A musket is a muzzle-loaded, smooth-bore long gun. ... (16th century - 17th century - 18th century - more centuries) As a means of recording the passage of time, the 17th century was that century which lasted from 1601-1700. ... (17th century - 18th century - 19th century - more centuries) As a means of recording the passage of time, the 18th century refers to the century that lasted from 1701 through 1800. ...