Rocco and Eli restore a Cold War tank that has been inoperable for over 30 years, create their own version of a blunderbuss and help a customer identify a Japanese explosive device from WWII.

Rocco pitches the idea of constructing a suppressor for a Revolutionary War cannon; a Banditos client tasks the team with reviving his Browning M1919 machine gun; a customer has something mysterious from World War II.

Rocco raises the stakes when he wants to rush the modernization of a 1930s-era Tommy gun; they also assist a client with restoring a WWII-era flamethrower and another with identifying his 1851 Colt revolver.

Rocco wants to create a powerful black-powder bazooka, and tasks the team with equipping a motorcycle sidecar with a mounted assault rifle; Eli comes across a revolver fashioned as a throwback to the days of the Old West.

Rocco and Eli surprise the Banditos team with a Civil War Gatling gun and task them with making it hand-held and mobile; a client asks to have a 16th-century wall gun restored; other clients have a WWII Liberator and a Winchester 1873 revolver.

Rocco wants to create the ultimate 21-gun salute using a 21-barrel flintlock that fires all shots simultaneously; Rocco and Eli help restore a customer's M1903 Springfield rifle and come across Doc Holliday's derringer.