This modified rifle's handguard and attachments were most likely purchased officially for testing. In the US, a soldier can't purchase rail systems and modify their service weapon since the armorer has to deal with that. However they can get approval to use certain optics if their commander has the ability to do so. Such a thing is unit-dependent. So I would imagine that the Chinese who are much more strict in this regard wouldn't allow their soldiers to modify their rifle's fundamental components.
