A musket is an obsolete, but lethal in experienced hands, firearm. Like a rifle, it is fired from the shoulder. It has an unrifled barrel, and, due to the lower muzzle velocity, usually had a larger projectile than an infantry rifle.
While muskets are useless in modern warfare, hobby enthusiasts use them in deliberately restricted target shooting and hunting, and also in historical reenactment.
Muskets use black gunpowder and are muzzle-loaded. The actual firing mechanism can be matchlock, flintlock, or a striker on a percussion cap.