I have broken the tiniest one, but the rest have performed wonderfully for me for probably 25 years. And frankly, with these ultra tiny screws and ultra tiny slots and their required ultra tiny screwdrivers, I think we're asking too much of them. I've broken Grace screwdrivers too. I don't know if there is such a thing as an indestructible screwdriver, especially in the smallest sizes.
For traditional muzzleloading guns, you should never have any of these itsy bitsy screws (except for maybe the trigger set screw...which isn't tightened anyway).
If I were doing a lot of modern guns with small screws (I don't do so much of that anymore), I'd probably get a set with the little removable tips and/or just grind some of the tips myself... and then promptly lose them! :haha: I need actual full size screwdrivers!