User blog comment:AugFC/An in-depth look at AW's weapon design/@comment-2163805-20141226213118

The Atlas 20mm actually has some resemblance to the Barrett M82A2 (bullpup variant), and it's used by two enemy snipers in "Utopia" after the player gets out of the sewer, though it is unobtainable, because we can't reach their position.