.
...not sure if anyone has mentioned it yet, but a good point on a center punch, used to mark your start point for drilling with an indent, is usually enough to keep the drill bit from wandering around as you start. If you're careful.


With what you've got there now, I'd be tempted to just drill one of those holes all the way through. The enlarge it a little to the size you need, and rethread it. I presume you're just going to mount another rack.