Originally Posted by JonM
This is a good point. Drilling these old mauser and springfield actions is like drilling granite with spaghetti if you don't have specialized machine tools.
The typical smith has drill presses and low end mills. You need a mill or press and bits designed to do this sort of thing and those aren't common or cheap and won't be found in a typical gunsmith shop.
though i have never broken one in a gun before, i have broken drill bits and taps in other things like engine parts and such, and it's not fun in the least to get them removed.
i have heard that some of the older rifles had some hard steel from others who have tried to drill and tap them.