Machine gun
Machine guns are weapons which fire small projectiles at an incredibly high rate. You would think that the Transformers would make something flashy or nuclear, but hey, go with what works.
Fiction
Generation 1
Marvel The Transformers comics
Dirge carried two air-to-air missiles and two automatic machine guns. Dirge's Universe profile In jet mode Dreadwind was armed with air-to-air missiles, thermal melters, rapid-fire machine guns and lasers. Dreadwind's Universe profile In robot mode, Fortress Maximus had twin wrist-mounted automatic machine gun batteries. Fortress Maximus's Universe profile Skywarp was armed with a heat-seeking missile launcher and a variable-calibre machine gun. Skywarp's Universe profile Caliburst transformed into an automatic machine gun, which shot 1,200 rounds of armor-piercing shells per minute. Slugslinger's Universe profile
Dreamwave Generation One continuity
In helicopter mode, Crossblades's Pretender shell was armed with 35mm machine guns, air-to-air missiles, and a thermal cannon. Crossblades's More than Meets the Eye profile Dirge was armed with high-velocity machine guns in both modes. Dirge's More than Meets the Eye profile In vehicle mode, Dropshot's turret could act as a machine gun, launch explosive shells, or operate as a flamethrower. Dropshot's More than Meets the Eye profile Groundshaker's ATV had high-velocity machine guns and sonic boomers as secondary armaments to its X-ray laser cannon. Groundshaker's More than Meets the Eye profile In vehicle mode, Growl had a roof-mounted machine gun that became his rifle in robot mode. Growl's More than Meets the Eye profile Half-Track was armed with anti-aircraft machine guns in vehicle mode. Their effectiveness was increased by his high-definition target-acquisition software. Half-Track's More than Meets the Eye profile In all modes Metroplex had access to a devastating arsenal of weaponry, including MASER cannons, ion pulse rifles, machine guns, missile launchers, and more. Metroplex's More than Meets the Eye profile Neutro wielded shoulder-mounted machine guns in robot mode. Neutro's More than Meets the Eye profile In jet mode, Nightflight was armed with a nose-mounted machine gun. Nightflight's More than Meets the Eye profile Overload's trailer transformed into a jet with double-barreled machine gun turrets on its wings with a laser-guided targeting system. Overload's More than Meets the Eye profile In jet mode, Powerglide was armed with concussion bombs, machine guns, and a nose-mounted thermal cannon. Powerglide's More than Meets the Eye profile Top-Heavy had two shoulder-mounted machine guns that fired electrically charged particles. Skyfall's More than Meets the Eye profile Skywarp was armed with variable-caliber machine guns. Skywarp's More than Meets the Eye profile Caliburst transformed into a machine gun that fired 9,960 armor-piercing shells per breem. Slugslinger's More than Meets the Eye profile
Beast Wars
Tarantulas and Blackarachnia had the legs of their spider modes equipped with machine guns. According to some sources, this specific type of machine gun carries the name "Neo Round Machine Gun." Blackarachnia Chapter
Although they are better known as the "Chainguns of Doom," Rhinox's twin gatling guns have been referred to as "Gatling Hammers" as well. Rhinox Chapter
After his upgrade into a Transmetal, Tarantulas had machine guns installed in his shoulders.
Beast Wars Neo
The Maximal Colada is armed with an "Arm Machine Gun". Colada Chapter
Unicron Trilogy cartoon continuity
Cybertron cartoon
Megatron gained a second Cyber Key-activated weapon called a "Death Machine Gun." It was capable of firing off several energized shots in rapid succession, thanks to its four barrels, and was responsible for bringing Hot Shot, Red Alert, and Scattorshot to the brink of death in the Battle of Niagara Falls. Revelation However, it would not prove as effective afterward, as Megatron's enemies either learned to evade the shots, or could better endure them.
Live-action Transformers movies
After arriving on Earth, Starscream and Blackout downgraded their plasma cannons for machine guns (the other Decepticons presumably followed course). This loss of advanced weaponry was presumably to better disguise themselves for combat on Earth. Prime Directives issue 4
The Autobots, on the other hand, retained their energy weapons. Only Ratchet was shown using a machine gun. Transformers Really thought that one through, didn't you, Starscream?
As more Transformers made their way to Earth, they also adopted machine guns. Arcee, Sideswipe, and The Twins all had machine guns. During the final battle in Egypt, all the Decepticon protoforms used machine guns, either wrist mounted ones or hand held rifles (one protoform switched to the wrist mounted one after his hand held one was destroyed). Revenge of the Fallen
Games
War for Cybertron
Machine guns such as the X12 Scrapmaker were used even before Transformers came to Earth, alongside their familiar energy weapons, during the Great War on Cybertron. Some Transformers had machine guns mounted on their vehicle modes, usually Scout Class warriors. Transformers: War for Cybertron