Once again a kitchen gunsmith has made life hard by ruining the head of a deep-seated screw by using a conventional ‘DIY or engineers’ screwdriver.
WHY DO SO MANY PEOPLE DO THAT!
The proper gunsmiths screwdrivers are hollow ground and parallel tipped to maximize the contact area of screwdriver to screw head.
Thus force can be applied without deforming the screw head!
It’s not like a set is expensive so do your guns a favour, BUY THE RIGHT KIT!