Committing a failed experiment. HeldEntities can now access inventory for reloading which is not that of a player. For example the inventory of a gun turret that they're in. Have the heli gunner control the turret gun as if they're holding it. Removes most of the need for duplicate code, passing inputs to the server side etc. But too many changes required in the end. However, this is all complete apart from syncing the attack heli turret inventory contents to the client.