There are, or you could look for a hole saw...get the right one and it'll do for the bolt hole as well
For a one off, it may not be cost effective, but if you're going to bung half a dozen on
, it may well be worth a punt
Should be OK with a pistol drill.
Run a pilot hole first (ie the bolt hole size) and clamp the tube down. If you struggle, run a drill through between the two sizes