Without a milling machine or a lathe, achieving perfect axial alignment
will be difficult if not impossible. You can get close, or even perfect
if you're lucky, with a drill press. Drilling by hand you will ruin the
collet chuck.
Drills are not precision instruments. They like to wander, even once
they're in the bore. Guiding a drill by hand to achieve perfect
alignment of any sort is not possible, at least not to machinists'
tolerances.
The minor diameter of M12 is 10.106mm. This is the size of pin you would
need to set the alignment with the drill's quill. A 10mm pin will still
allow 0.1mm, 0.004", of slop. And it's likely that the minor diameter of
the chuck is a bit larger, to ease threading on a spindle nose.
Also, the drill bit should be as short as possible. Drills flex. Using a
screw machine bit (stubby bit) will help.
And, of course, you'll need to find a way to fixture the collet so it is
immobile once it's aligned and on the drill press table. The usual kind
of drill press vice does not hold round objects in a vertical
orientation very well.
Still, as you can find M14x1 collet chucks on Amazon fairly
inexpensively, you won't be out much if the enlarging doesn't work out.
Best of luck.
--
Elliot Nesterman
elliot@...www.ajoure.net
"The finest jewel cannot disguise a flawed character."
Steve Johnson