I can tell you from recent personal experience that drilling holes in SS is a MASSIVE PITA. I just burnt out 2 drill bits trying to drill out my Helio clone yesterday. At one point the thing got so hot that the drill bit snapped off and actually welded itself into the hole I was trying to bore out. Crazy.
Several things you need to know: Make sure you are using hard bits, cheap ones wont do it (this means avoid harbor freight and cheap home depot bits). Also, the bit must be sharp and you must keep it wet with lubricant... even motor oil is acceptable. And the most common mistake people make is overspeed. You have to use lighter pressure and a low speed setting on the drill. Stop occasionally to allow it to cool.
