Machine Gun

A Machine Gun (MG) is a fully-automatic weapon that fires bullets. In ShackTac, the term only refers to weapons of approximately .50 cal (12.7mm) and smaller. Machine Guns are some of the most common weapons on the battlefield, carried by both Infantry and all manners of Vehicles and occasionally seen as a static emplacement.

Machine Guns are used to rapidly "saturate" a target area with multiple projectiles. This increases the chance of hitting the target, and also has the effect of suppressing infantry. Machine Guns can therefore be used either to kill a target or to simply scare it and prevent return-fire, or to deny enemy movement through an area.

Machine Guns can expend ammunition very quickly. To facilitate the high rate of fire, they are typically fed from Belts or large ammo Boxes. Some (particularly small ones) are fed from large or even standard Magazines. Even the smallest Machine Gun is fitted with a Bipod or Tripod to provide it with stability when firing, due to the strong recoil produced when firing on full-auto. Most Machine Guns cannot fire selectively at all (single shots).

Machine Guns are primarily useful against enemy infantry, but can also defeat Light Vehicles fairly easily. The largest machine guns have enough power to get through a small amount of armor, but are near useless against heavy armor. They can at best hope to strike a heavy vehicle's externally-mounted equipment, but are unlikely to disable the vehicle altogether. A powerful machine gun may, in some circumstances, pose a threat to Helicopters, but is rarely useful against Jets.

Machine Guns are divided into five different sub-classes based primarily on their caliber. They are the Automatic Rifle, Light Machine Gun, Medium Machine Gun, Heavy Machine Gun, and Rotary Machine Gun. A Machine Gun whose caliber exceeds ~14.5mm is called an Autocannon, and is technically a separate class of weapon.

Specifications
In general parlance, a "Machine Gun" is defined as any fully-automatic weapon that fires bullets. This definition is a bit broad in the modern context, and has therefore been narrowed to refer to a class of similar weapons of a certain caliber range that are only capable of fully-automatic fire. This narrower definition is the same one used in ShackTac, with a few minor differences.

A Machine Gun is structurally similar to an Assault Rifle, with a firing mechanism that utilizes the power of a fired bullet to load the next bullet into the chamber. This allows the weapon to continue firing as long as the trigger is held down, or until it runs out of ammo. Machine guns in general are not capable of semi-automatic fire - firing a single bullet per trigger pull - although a skilled gunner may be able to do so with some reliability anyway using careful trigger pulls.

Most (but not all) Machine Guns are classified as Small Arms, firing either "intermediate-powered" bullets (approx. 5.5mm in diameter) or "full-powered" bullets (approx. 7.62mm in diameter). They are light enough to be carried by infantry traveling on foot. Ammunition in combat-sufficient quantities, however, is typically heavier than the weapon itself, requiring other infantrymen to carry additional ammo for the machine gunner; In some cases requiring an entire specialized infantry team to both operate the weapon and carry its ammo.

Other Machine Guns, especially those firing .50 caliber bullets (12.7mm) are significantly heavier and cannot easily be carried or even operated on foot. They are instead installed as mounted weapons on a variety of vehicles. Nearly every armed vehicle in the game has a machine gun, either as its main weapon or as a secondary weapon used for tackling enemy infantry threats.

The rate of fire of a Machine Gun is not significantly higher (if at all) than that of an Assault Rifle, but the fully-automatic nature of the weapon and the way it is used in combat means that Machine Guns expend ammo very rapidly. To aid in this, Machine Guns typically load their ammunition from a Belt containing an arbitrary number of bullets (typically 200 in ShackTac for infantry-carried Machine Guns). Lighter Machine Gun models may instead use ammo Boxes containing anywhere between 100 and 200 bullets each. The lightest Machine Guns actually use Magazines that are not much larger than an Assault Rifle magazine, sacrificing heavy fire for a more mobile and easy-to-handle weapon.

Sub-Classes
Machine Guns make up a large category of weapons which - while mechanically similar to one another - are used very differently based on their size, weight, and ammunition. Barrel caliber is the primary distinguishing factor, although there are several others.

Therefore, Machine Guns are separated into several distinct sub-classes based on how they are used in combat.


 * Automatic Rifle: These are very light Machine Guns firing bullets of 5.56mm to 7.62mm in diameter - the same bullets used by infantry Assault Rifles. They are carried by Automatic Riflemen who are an integral part of each Fireteam. Assistant Automatic Riflemen carry the extra ammunition for the gun. Automatic Rifles significantly improve the firepower of the Fireteam, especially against distant contacts or infantry in cover, but are otherwise similar to Assault Rifles. Due to the similarity, an Automatic Rifle can be reloaded with Assault Rifle ammunition, and may even be able to use standard Magazines. Common Automatic Rifles include the SAW, RPK, and several other models.
 * Light Machine Gun: A heavier variety of the Automatic Rifle, the LMG fires a heavy 7.62mm bullet that is not generally interchangeable with Assault Rifle ammo (though it might be). The added weight of the weapon, as well as the increased recoil, make it less useful on the move - but significantly more deadly when properly set up. LMGs are rarer in ShackTac than Automatic Rifles, but do appear often enough. Shackers rarely refer to them as LMGs, instead simply calling them "Automatic Rifles" due to being used in largely the same manner. Common Light Machine Guns models include the M240, M60 and PKM.
 * Medium Machine Gun: This is a Light Machine Gun that is carried and operated by a separate, dedicated unit (called an MMG Team). Due to being separate from the infantry Fireteams, the MMG Team has greater flexibility in its movement and positioning. Otherwise, there is no physical difference between an LMG and an MMG.
 * Heavy Machine Gun: A significantly heavier weapon firing .50 caliber (12.7mm) or larger bullet. They are deadly accurate, and have enough power to harm lightly-armored combat vehicles and Helicopters. They may be carried and operated by an infantry team (called an HMG Team), in which case they can only be fired when properly set up and must be disassembled when moving away. HMGs also feature very prominently as both primary and secondary weapons on all manners of vehicles, up to and including Tanks.
 * Rotary Machine Gun: This is a multi-barreled weapon that works the same as a Machine Gun, except it has several barrels that rotate around so that each barrel has a moment to cool down before it has to fire the next bullet - effectively providing the same effect as several machine guns firing together. These weapons have a very high rate of fire and are exceptionally deadly. Due to their extreme weight and recoil, they are almost universally found mounted on Aircraft, particularly as Littlebird guns and as Transport Helicopter defensive weapons.

Other Automatic Weapons
There are several other weapons in the game (and in real life) that could be classified as "Machine Guns" upon surface-level comparison, but are considered completely different weapon types.


 * Submachine Gun: A small personal defense weapon that can perform fully-automatic fire using pistol-caliber bullets (9mm, .45ACP, and so on). While the name contains the words "Machine Gun", these weapons are significantly more similar to Assault Rifles. They are very rarely seen in ShackTac, primarily as Air Crew backup weapons. They are not very combat effective except in very close combat.
 * Autocannon: At the other end of the spectrum, an Autocannon is essentially a massive Machine Gun that fires Shells instead of bullets - a caliber of around 20mm or higher. The shells are not only larger, but are often tipped with High Explosive warheads to increase their effect. These weapons are too large to be carried by hand, and are all found mounted on vehicles.
 * Some Cannons have a self-loading mechanism that technically makes them fully-automatic. However, the rate of fire is so low that the weapon cannot really be considered an automatic weapon. Even if they were classified as such, they would be Autocannons, not Machine Guns.