Infinite ammo on the PM73 RAK MAG.

I dropped the MAG to see what ammo was in it, empted the MAG in inventory reloaded, added MAG back to PM73 RAK, as seen in picture I still have the MAG in inventory and loaded in RAK but but is the same MAG so only have one. If I shot the RAK the MAG will empty, but if I move item in inventory the MAG reloads even when I have no more ammo.

Only shot once so MAG was at 14 rounds, when i moved item,so goes back to 14. {F31471} {F31472}