The RAC40-C (Reisser Arms Company Model 2540, Carbine) is an assault carbine produced by the Reisser Arms Company at the request of the HOA. Its design is based largely on the earlier RAC-22, a weapon notable for its use of multiple barrels and caseless ammunition. It is currently the service rifle for most human-based military powers including the HOA and Elliot's private army.
The RAC40-C is the carbine variant of the RAC40 platform, and is essentially just a shortened version of the parent rifle with a faster rate of fire. It features a bullpup design, meaning the action is located behind the trigger, opposed to in front as with conventional designs. It is a break-action weapon, meaning that the barrel is hinged to the bore axis (similar to a double-barreled shotgun). Magazines are loaded directly into the six barrels, with each one holding upwards of 60 rounds (for a total of 360 per full reload). The caseless bullets are propelled electronically, and can be fired at 5600 rounds per minute (RPM). The rate of fire can be altered to a steadier pace by the use of a built-in console. The RAC40-C fires the HOA standard M331 5.54x21mm FMJ ammunition, although it is compatible with various kinds of ammunition such as Drill and Incendiary rounds. The RAC40-C features a modular design, allowing it to be extensively altered and modified with various optics, flashlights, sound suppressors, and under-barrel grenade launchers.
Since its inception, the RAC40-C has been seen as humanity's "flagship gun". It is featured prominently by the Reisser Arms Company as a sort of mascot firearm, and it has been nicknamed the backbone of the HOA.