well moderately deep anyway. In this case, 8mm dia and 65mm deep.
This is a hole in the end of a bit of BMS bar, so the bar is in the lathe and the drill in a chuck in the tailstock. First 25-30mm goes fine and then the deeper it gets the more the swarf doesn't clear from the drill bit flutes, and in the end I have to wind the drill back out to clear it.
Using cutting fluid seems to make it slightly better although it still happens.
Initially, the drill makes nice long curly bits of swarf, but they get shorter the deeper it gets, till it only makes little bits which don't find their way out.