A coaxial machine gun is a machine gun fitted to a coaxial mount as a secondary weapon beside a vehicle's main weapon. This allows the machine gun to be aimed by use of the main gun control. It is used to engage infantry or other "soft" targets when the main gun's potential collateral damage would be excessive, or to conserve its ammunition.
Coaxial machine guns are mounted on light and heavy tanks. They are very effective against infantry and light vehicles, although with limited ammo (400 rounds) and a relatively short overheat time. As with main guns, there is no difference in performance between those mounted on Allied or Axis tanks.
Their stats are identical: although multiple variants of the Type 85, PKT, and M2 Browning appear, the coaxial variants have no difference. They each feature low spread, a moderate rate of fire, a high damage, and infinite ammo. However, each one is also prone to overheating with prolonged fire.
Battlefield 1943 features coaxial machine guns mounted on the tanks for both factions are an MG34 or an M1919. IJN tanks have a similar kind of coaxial machine gun for balancing reasons. The coaxial machine gun is very effective against infantry, aircraft and jeeps. The coaxial machine gun is also surprisingly very accurate for a machine gun and can easily obtain headshots at medium range.
Battlefield: Bad Company 2
- Main article: Alternate Weapon Package
The UAV-1 also gains a machine gun in addition to its guided rocket. It functions nearly identically to its MBT counterpart.
In Battlefield Play4Free, players can add a coaxial machinegun to any heavy tank by choosing the Tank coaxial machinegun training. It can be seen as more effective against infantry than the main gun.
Allows the player to use a coaxial machine gun for tanks and increases the ammunition capacity for the machinegun with further ranks. Spending at least one point in this option greatly increases the efficiency of main battle tanks against infantry. It is more useful in large maps like Karkand.
- Allows the secondary coaxial machine gun to be fired when driving tanks with 25 rounds.
- Increases the ammunition capacity to 35.
- Increases the ammunition capacity to 45.
— Battlelog Description
Coaxial LMG is a specialization that provides an MBT, IFV or Tank Destroyer driver with an anti-infantry secondary weapon. Depending on the vehicle, either the M240C or PKT light machine gun is mounted in-line with the vehicle's main weapon. They can be used by M1 Abrams and T-90 MBTs, the LAV-25 and BMP-2M IFVs as well as the M1128 Mobile Gun System and the 2S25 Sprut Tank Destroyers.
Its high volume of fire provides excellent suppression against infantry, at the cost of the occasional overheat. The reticle is composed of a partial crosshair and box corners with a center dot.
Each bullet inflicts 20.0-15.6 damage, somewhat less than the infantry LMGs. However, tank users benefit from completely steady fire free of recoil, and the tank's armor and mobility. The 610 m/s muzzle velocity is comparable to the M240B, average among LMGs.
— Battlelog description
Compared to the Coaxial LMG, it benefits from a much higher damage per individual bullet, at a max of 50 trailing down to 34, and a higher accuracy, at the cost of firing at a significantly slower rate of fire. Unlike the Coaxial LMG, the HMG does not overheat, allowing for continuous fire.
The HMG can engage infantry at any range, and is the single most effective long-range anti-infantry tank weapon, with the first three shots retaining perfect accuracy.
It deals 34% damage per shot at full dropoff, so it will kill in three shots in normal mode and only two in Hardcore mode.
The HMG also has the fastest bullet velocity in the game, clocking in at 750 m/s, reducing the amount of leading and bullet drop compensation needed for moving targets. In Hardcore, it can one hit kill at any range if it hits the head, or a chest shot and higher at close range.
Unlike the LMG, the HMG can damage lightly-armored vehicles, including jets and helicopters. Its high velocity, however, is offset by its low fire rate in anti-air combat, as well as the tank turret's slow traversal and low gun elevation.
As the Canister Shell is more forgiving in aim and deals excellent damage, it is generally more effective against air targets within close- to medium-range.
The Coaxial HMG is larger than the LMG, so it is mounted above the main cannon rather than through the traditional gun port, and is easily seen in first-person view.
After the 1.04 Patch the fire rate of the HMG is much higher than before, while still avoiding overheating. The Armored Kill patch gave it greatly increased accuracy.
— E3 2013 alpha gameplay
The Coaxial LMG is a vehicle specialization featured in Battlefield 4, functioning similarly to the one seen the Battlefield 3.
The Coaxial HMG is a vehicle specialization featured in Battlefield 4. Its use is unchanged from Battlefield 3, providing an effective long-range solution for infantry and light armored vehicles. It is slightly inaccurate during long bursts, and unlike its Battlefield 3 counterpart it will eventually overheat, though it's hard to do so because the overheat time is so long. It has a 50% higher rate of fire than in Battlefield 3, at the cost of muzzle velocity being reduced from 750 m/s to 500 m/s, making shot leading essential at longer ranges.
In Battlefield 1, two vehicle packages arm the driver with a coaxial Hotchkiss M1914 8mm machine gun. On the Standoff Assault Package, it is a secondary weapon, and is the same front machine gun used by a separate gunner on other assault tank packages.