Albo, when you go back to drill that last hole, and you can't snug up that drill bit any further than, one option may be to buy a cobalt bit (less likely to deflect,) or sacrifice/shorten a normal drill bit so you can snug it up.
Another option is one of these hollow shanked chucks,
and you can shove the bit right up it,
I bought that from Lee Valley a few years ago and they haven't had in stock since.
If your first cut is too short... Take the second cut from the longer end... LBD
