The body of an Armstrong Arrowgun is shaped like an arrow cross. It is black and white with red edges. The barrel is long, black, and cannon-like. The handle is black and the guard is red. The guard is lined by six black diamonds with light tan edges. The diamonds flash violet, the color of the bullets, when Xigbar reloads. The shots produce red sparks on contact with enemies and gold ones on contact with anything else.
Unlike most of Xigbar's Arrowgun, the Armstrong and Armstrong+ are only fired in their combined rifle form. The ground combo consists of Xigbar combining his guns and firing a single, powerful shot straight forward. The alternate combo cancels the shot, with Xigbar flipping backwards, separating his guns. It can be activated before the shot is fired.
The aerial combo consists of Xigbar standing upside-down in the air, combining his guns, and firing a single rifle shot straight beneath him. The -Combo cancels the shot, with Xigbar dropping to the ground right-side up. It can be activated before the shot is fired.