The AUG is a fully automatic weapon, unlocked at level 32.
The Armee Universal Gewehr, or 'universal army rifle' was one of the first successful Bullpup assault rifles, with the weapon action and magazine behind the trigger - closer to the shooter's shoulder than in a traditional design.
It's an Austrian weapon, manufactured by Steyr. The first AUG variants were designed in 1977, with the HBAR following some time after. The AUG assault rifle entered service with the Austrian military in 1979.
It fires the NATO standard 5-point-5-six by 45 millimetre intermediate cartridge, typical for an assault rifle or light machine gun.
The HBAR variant of the AUG is essentially the same as the standard variant, with a longer and heavier barrel designed for sustained automatic fire without loss of accuracy. 42 round magazines are used instead of the more standard 30.
The AUG is normally seen with its integrated Swarovski telescopic sight, but this is not present in Modern Warfare 2's multiplayer. Instead, the backup iron sights are used.
The AUG HBAR combines some of the best features of both the LMG and Assault Rifle categories; You have the high power of the LMGs, particularly at range, with the reload and handling of an Assault Rifle.
Recoil is present but relatively mild, and can be handled at longer ranges by burst firing.
It is classified as an LMG in game - so your mobility and aim speed will suffer when compared to an assault rifle. Compared to the other LMGs the magazine capacity is less generous too - at just 42 rounds it's about the same as a typical Assault Rifle with extended mags.
Nevertheless, with the right loadout the AUG is a formidable weapon, with sufficient firepower to tear through an entire team.
The AUG suits an aggressive style of play, but suffers from the poor mobility and aim speed of the LMG class.
It works well against groups of enemies, especially when you can take them by surprise. It might take a while to get into position, but if you can flank the enemy you'll be able to do some serious damage.
When moving with the AUG it's best to take things slowly as you approach; Be ready for an engagement if neccesary, and be ready and aim down the sights when approaching chokepoints and likely encounters.
After you fire it's best to keep moving, unless you anticipate more enemies moving to your revealed position. If you are expecting an attack, make sure you are firing from a covered position - it will tilt the odds in your favour.
Don't be afraid to fall back if you feel like you're getting overwhelmed - if you need a reload it's better to do it out of the open.
Once the coast is clear, continue moving forward, slowly closing the vise, ideally driving the enemy into a spawnlock or pushing them against your teammates in a pincer-like movement.
With patience and good awareness you can push through entire teams. The element of surprise should be part of your strategy, but once broken you can still force the enemy into your sights on your own terms by pushing forward with good use of cover.
Sleight of Hand Pro is a must, bringing the aim speed in line with an SMG without the perk, and allowing you to cope better in situations where you are caught in an unexpected engagement.
Scavenger isn't usually needed as you get more ammunition than you would with a typical assualt rifle, 126 rounds total by default. Even without scavenger, you don't have to worry about running out too often.
Packing a decent close-quarter secondary can round out the AUG's abilities and make the ammunition supply even less of an issue.
My usual preferred equipment are stuns and semtex; Stuns are faster-throwing than flash grenades, which is very useful for an assault class - and Semtex makes for a useful tool to flush enemies out of buildings and around corners.
Grenades can also be used in a defensive manner as well as an aggressive way - if you need to retreat to reload or take cover, throwing a semtex toward the enemy will deter them from pushing towards you for a moment, giving you precious seconds to fall back and recover.
The AUG is a high-powered weapon, dealing two hit kills at all ranges when paired with stopping power. It's as controllable as most assault rifles and effectively comes with Extended Magazines for free.
It does come with a mobility penalty, but for the patient player with a good awareness of enemy location, the AUG can be used to aggressively contain the enemy while slowly driving them back.
The quick time to kill and healthy magazine size mean that once you're in position, you can tear through groups of enemies, hold a spawnlock, and rack up some impressive killstreaks while doing so.