You know one of the most used/abused tools most people inflict upon their firearms are screwdrivers.
I cringe every time I pick up a used and sometimes a new firearm with galled slotted screws. It devalues your firearm by more than what a properly fitting screwdriver would cost.
Those galls happen because of poorly fitting screwdrivers as well as improper use of screwdrivers.
Slotted screws are the worst method used as a retaining device. Many years ago it was understandably about the only practical design other than a square head screw that would always be proud. The advent of counter sunk and even thin head slotted screws was a great advance. Today they just aren't necessary. Philips, Allen, Torx, Robertson are among the best suited for firearms. Even those need to have properly fitted drivers.
I am anal about properly fitting screwdrivers. I go to yard sales and public markets to pick out the best used screwdrivers they have at dirt cheap prices. I have at least 30 different widths and thickness flat screwdrivers. Even that isn't always enough and another custom driver needs to be ground. Every one of these drivers has cost less than a dollar. There are at least another couple of dozen in a bin awaiting their turn to become a custom fit driver. A loose fitting or to narrow or to wide driver is a recipe for a galled and sometimes broken or chipped screw head. Often, especially on antique firearms those screws just can't be replaced. Making them up is impossible if you don't have a lathe because often the threads are proprietary and made on a special hand made screw making machine or even hand filed. Standardized taps and dies just weren't available back in the day.
I loved it when Remington and others went to allen head torqueing screws. I prefer the allen head screws to torx. Small torx head screwdrivers are very positive but often the bits are brittle or weak and if they are to strong can be over torqued and break off the contact flanges.
Screwdrivers need to be chosen carefully and ground to fit as needed. Anything else cries amateur.
Don't get me wrong. I understand where you are coming from with those sets and they do have their uses if used sparingly and properly. The one good thing about them is that they are ground with "flat" surfaces. Other types are ground on a bias. The thing is the bits in those sets are either to narrow, to wide, to tight, to sloppy to do really good work. On the other hand they take up very little space in a drawer or on the bench. My screwdrivers take up a lot of room in my shop and space is getting to be at a premium. I have allowed it to become cluttered with to many projects, tools, tooling, machines, loading equipment etc. My New Years resolution is to clean it up and find a place for everything that is tagged and easily accessible. That will be a major chore.
Remember, the commercial mass produced screwdrivers we have available on the cheap need to be used and purchased with discretion. Mind you if that is all you have available????
A couple of small tricks to release over torqued screws. Clamp the part or firearm to be worked on in a vice or rifle work bench. This frees your hands and stops the drivers from slipping out and leaving an unsightly scratch on the metal or stock surfaces because the work is held in one hand and the other is on an angle to the screw.
The next is to apply a tight fitting driver to the opening of the screw head whichever shape it requires and give it a sharp rap with a hammer. Then, use a wrench as close to the screw head as possible to carefully turn out the screw. Be careful though sometimes they are lacquered in place or rusted. The rap you give the driver with a hammer will likely cause the rust to break up a bit and allow some Kroil or other penetrant to get in there and free things up after some soak time. Sadly, not always. That is where a tight fitting screwdriver comes to the fore. It can be heated up with a butane torch and the heat will transfer to the screw and soften the lacquer or loc tite. The heat will even help the rust to break up and allow more penetrant to get in.
Be very careful with those screw drivers and screws. I will discount the price of replacement screws from the value of the firearm when buying or doing an appraisal. So do most people that deal with buying and selling.