Gunsmith screwdrivers
Hardware store screwdrivers? Won't be buying any used guns from them.
If you must grind a screwdriver be very aware of the heat of grinding. Keep the steel cool. Grind and quench, grind and quench, ad infinitum...
An instant "no sale" is buggered screws. They are a red flag and indicative of the issues you can't see.
Quality hollow ground screwdrivers, I like Wiha, not cheap. I have Wiha drivers that were used when I bought them, and I have had them more than twenty years.
There is no requirement that they be labeled gunsmith, they must fit, close only counts in hand grenades and nukes. They must fit! The gunsmith sets typically have far more sizes of common screw drivers.