The Machine Gun is the main upgrade weapon in Metal Slug: 1st Mission.
It is very similar than Heavy Machine Gun but this one has a low firepower. The player can also shoot diagonally, unlike the Heavy Machine Gun's arced bullets, but only when in the air.
It is the only weapon upgrade in Metal Slug Mobile.
|Standard||Handgun (Murder .50AE | Murder Model-1915 .38 Mk.1Am) | AR-10 | M-3685 | M60|
|Limited|| Heavy Machine Gun | Rocket Launcher | Flame Shot | Shotgun | Laser Gun | Iron Lizard | Super Grenade | Enemy Chaser | Drop Shot | Two Machine Guns | Zantetsu Sword | Thunder Shot|
|Bombs||Grenade | Fire Bomb | Stone | Earring Bomb | Smoke Bomb | Monolith | Snowball|
|Melee||Knife | Tonfa | Hatchet | Tomahawk | Punching Glove | Stun Gun | Wrench | Vulcan Punch | Argentine Backbreaker | Moon Slasher|
|Other||AA Machine Gun | Thunder Cloud | Mobile Satellite|