[mactec54]

Depending on the hole size, I kept a load of broken end mills of varying sizes.
I use the shanks of these fitted into the spindle nose to line up to a drilled hole. Generally between sizes 3-8mm.

Broken End Mills, where do they come from, I have hundreds of End Mills but no broken ones.

Yes this is a way to do it if you have +/- .005" on a part tolerance.

Gauge Pins or bar stock work for this rough hole location method as well.