The M249 exists in most games in two versions: Either the M249 Para or the M249 SAW. The Para is konfigured for paratroopers mainly, this means, it has a shorter barrel, which makes it more easy to use in CQB environment. The SAW (means: Squad Automatic Weapon) is used mainly for supressive fire, the barrel is longer. This makes the SAW more heavy than the Para, but it also gives a better acuuracy when firing in full auto mode.

The M27 is based on the H&K M416 assault rifle.

The MG3 is pretty old, it entered service in the german forces between 1950 and 1960. MG stands for "Maschinengewehr" (german for "machine gun"). This is an old machine gun, based on the MG42 from WWII. Real Life vs Games: The MG3 cannot be used by one person alone. When shooting Rambo-style it is impossible to hit something. As you see in the pictures, you need a Bi-pod or a person who acts as some kind of bipod. Is it still in use? Yes, even though it's very old, the MG3 machine gun is used on the Leopard 2 tank (and other vehicles).

MG36 machinegun Heckler & Koch The MG36 is a variant of the Heckler & Koch G36 assault rifle.Main difference between MG36 and G36 is the barrel: the MG36 has a heavier barrel for increased heat resistance.  

The M134 minigun is used in the Blackhawk helicopter, on a HMMWV, in a jet or even on small helicopters like the Little Bird... but due to it's recoil it is simply impossible to shoot it from the hip like rambo does, lol :). On the other hand it is total nonsense that planes like the warthog would fall from the sky due to it's recoil.

... no info yet...

The RPK-74 is newer version of the RPK machine gun. As the name displays, it was introduced in 1974 together with the "new" AK-74 rifle.Main difference is the different caliber and the slightly bigger ammo box: the RPK can hold 30 rounds in the box, the RPK-74 can hold 45 rounds.

LA80 L86 LSW

http://www.knightarmco.com/lmg.html

Difference to other XM8 variants: Integrated bipod heavy 20" barrel for continuous fire 100 rounds drum magazine Real Life vs Games: The XM8 series never left prototype stage, no army in the world uses it as a regular weapon.