I extracted the model and to my surprise there was a hidden box magazine within. Unfortunately, I couldn't manage to just un-hide it, so I edited the model instead. While I were at it, I also changed its barrel length and rail setup to better match the real life counterpart, the SKO-12 Shorty (not Mini, as the Mini has a longer buffer tube). Basically, I made it because it looks incredibly silly when the huge drum magazine clips into the ground most of the time.