An electron gun is a device for generating an electron beam.

He is known as a French musketeer.

He shot the enemy with a machine gun.

He went to try out his new air gun.

He headed to the battlefield with an assault rifle.

He defeated the enemy using a sniper rifle.

The police used a water cannon against the demonstrators.

This story perfectly practices the principle of Chekhov's gun.

He led the army as a cavalry general.

He likes to take a walk in the park at dusk.