Steyr AUG at Battlefield Vegas.
It’s a 556 bullpup with a short stroke gas piston as most of you probably know. Developed in the 60s then adopted by Austria (also the birthplace of the Glock) in the late 70s, but always thought of as one of those 80s bullpups.
Original versions used proprietary translucent 30 round magazines but more modern iterations are fed by STANAG/PMAGs, including the example demonstrated here. With the modularity of the quick detach barrels and receivers there are all sorts of variants of the AUG that can be quickly assembled, from 9mm SMGs through to 556 carbines, rifles, DMRs and even an open-bolt auto-only LMG that had 42 round specific mags back in the day.
The main components in the trigger pack (hammer etc) are actually made of plastic and with all the other plastic used this is a seriously light gun but recoil is on the light side even for 556, easily controllable when firing automatic, the designers did an excellent job in that department.
Another weird and unusual feature is the progressive trigger, whereby if you pull it half way you fire a single shot, then if you keep pulling the gun goes in to auto. Interesting way to reduce the number of controls on the gun but not so good under stress and duress; demonstrated by the fact that major adopters of AUGs including the Republic of Ireland and Australia opted for a version of the trigger that can lock out the automatic fire via a small button which can be pressed in if and when automatic is specifically desired.
Other notable adopters of the AUG include New Zealand (who since switched to LMT ARs) and of course Austria themselves. In smaller quantities it has seen service with the special forces of various small nations, as well as the ICE federal law enforcement agency in the US and the Falklands Islands Defence Force, amongst others.