I tested in three high tier weapons. Everytime I press R to connect a new fully loaded magazine into my gun, the animation works good but the mag doesn't change. But in the inventory details shows the full mag is on the gun. And when you shoot it results in ghost bullets. The problem is fixed after disconection and joining the game again. Once you restarted the game the empty or half empty magazine it's on the gun and the inventory details shows the actual reality. The problem does not happen when you change the mags using the hold and drag option. Just happens when using the long press R.