I got that same set of drivers. They wont slip out of the slot as bad as regular drivers but they are kinda brittle. I did break one of the small ones trying to remove a scope on a rifle I bought.
I finally got out the dremel and cut it off, They must have used red loctite on that one.
That's generally the idea with quality gunsmithing drivers.
Sometimes it's better to have a sacrificial tool that breaks before a screw that may be difficult costly or impossible to just replace.
If time is money, I figure most gunsmiths would rather not have to source or make a screw to get a gun out the door.
They're always modifying drivers to fit, so it's probably no big deal to just fix the tip when needed.
I think that's probably why a lot of gunsmiths just go with multi bit options.
Brownells, Chapman, WFMC, or the Grace bit driver, because bits are cheaper to replace.
That's why I really love my Chapman set, that plus the versatility with all the bit extension and handle options.
I'm often using as many as 6 different sizes though, and switching between my 5 driver handles sometimes gets annoying so I decided to add a set of fixed drivers to my arsenal.
I do a little on firearms, but it's mostly vintage airguns and vintage fishing reels.
