Drilling sidepipes to quiet the rattle

[427BDR]

After reading recommendations here I picked up self tapping screws and I'm going to drill the side pipes to hopefully put an end to the annoying rattle.

Question for those who've done this before, do you drill the screws all the way in until they are flush, or do you drill them in just far enough so the screw is just pressing against the baffles and applying enough pressure to hold / pin the baffles in place.

thanks in advance