There’s a couple of things immediately come to mind.
- I believe stainless work hardens when being machined so you need to keep a minimum chip thickness to avoid it turning into unobtainium and trashing the cutter. If you’re in Fusion there’s both the feed per tooth on the tool tab and pitch or ramp angle on the passes tab, are you going down into the hole fast enough to not work harden the bottom?
- When executing a bore or any similar narrow radius toolpath we have to compensate for the ‘effective feedrate’ of the outer edge of the cutter which is travelling in a circle of 1 x cutter diameter greater than the toolpath circle, in bore operations it’s pretty easy to accidentally feed the outer edge of the circle at 2-3x the feed rate you keyed in. There’s an excellent Haas video about this which was pointed out to me in this thread
Others with more experience may have a view on whether to drill first in a peck cycle to keep the hole cool.