The system relies on a low-mass bolt and carrier and a dimensionally stunted system linearly limited by the tangential bolt thrust of the intermediate cartridge the carbine fires.
Vis a vis, it isn’t as overall reliable especially once fouled vs say, and AK that used a proper short stroke system with a much more inertially potent BC group to help feed cartridges.
When properly balanced with correct recoil spring and a thoroughly cleaned gas system, and fresh magazines, the carbine works well.
Introduce any amount of fouling or grit and it becomes an iffy proposition at best. Doesn’t help the tappet, once fouled, is tough to get apart to clean.