The Machine Gun Was Shown at the Beginning. Sir, Times Have Changed.

A young man travels through ancient times, holding a book "History of the Development of Firearms". Burst gun: uses a bamboo tube as the barrel to fire projectiles, and can only be used once. Matchlock gun: Fold the matchlock and ignite the propellant. The reloading is a bit slow. Flintlock gun: Abandoning the match rope, the flint on the hammer is struck to generate sparks to ignite the gunpowder. Rifle: breech loaded, rifled. Machine Gun: Fully automatic, fires bullets in rapid succession. Sir, times have changed!