The term 'OLD FIREARM' can be summarized as a MUSKET, which is a 6-letter word. A MUSKET is a muzzle-loaded, smoothbore long gun that appeared in early 16th-century Europe and was used until the mid-19th century. It was the first firearm to be used in battle and was widely used by infantry troops. Muskets were typically made of iron or steel and were fired using a matchlock, flintlock, or percussion cap mechanism.