The FN P90 (matching the text in the pic):
Not only did the FN P90 fire a revolutionary and original ammunition, but it also marked the advent of two significant technological events in the history of gun making at FN. First of all, its patent specified the placement of the 50-round magazine along the barrel and axis of the weapon, while all the machine pistols of the time were still encumbered, either laterally or vertically, by their long magazines. Furthermore, through the power of its spring, the FN P90 magazine itself ensured the rotation and exit of the ammunition into the gun’s chamber. Also, for the first time in FN’s history, the development team chose to put their faith in the possibilities offered by technical polymers. This choice placed FN Herstal definitively at the forefront of high tech technologies. More than 50 percent of the new arms later developed by FN Herstal would be made of composite materials.
Also famously used in the defense of Earth against the Goa’uld
i truly do not understand just exactly what the hap is fuckening here
My best guess is a proof of concept of the idea of rotating bullets 90° for their desired mag geometry.
Here’s the final version of the concept.
