Originally Posted by martini
Agree you should get away with hss bits if theyre smallish holes. Couple of tips I would give are keep the rpm's down and apply as much pressure as you safely can instead, also get someone to squirt coolant or water on the tip, if the stainless gets too hot even James Bond won't have anything to touch it!
This is top advice. I can confirm all is correct and can only wish that I had asked the question before I wrecked a swathe of destruction through my bit collection and learned this by, well, mostly error