The correct order is handaxe, sword, rifle, gatling gun, nuclear bomb.
The handaxe is a Stone Age weapon that has existed for more than one million years and long predates homo sapiens. The earliest swords were invented around 3,300 BC in Europe during the beginning of the Bronze Age. The first rifles were likely developed during the 15th century, although their exact origins are unknown. The Gatling gun was invented in 1862 and was first used in battle during the US civil war. The nuclear bomb was invented in 1945 as part of the Manhattan Project.