Whenever you use screwdrivers on a firearm always use gunsmithing screwdrivers the blade is straight and not tapered this insures that the screwdriver won’t walk up the slot and ruin a perfectly good screw. Also make sure the blade fits completely in the slot and fills the slot as well. This will prevent damaging screw heads. I often see collector guns get spoiled just because someone used an ordinary screwdriver on gun screws. The heads are usually torn up.
These can be fixed to look like new with careful re-cutting and filing the screw head and then re-bluing the screw but it is easier to use the proper tool for the job!!