Coring through Ohia Logs

[all bent]

As I mentioned in an old thread found as I scoured google for some sort of guidance, my company has been contracted to install signs and sign posts for the State and the plans call for drilling a 3" hole, 2 feet deep into ohia logs. We have been using 3" forstner bits on drill presses as well as a 1/2" hole hawg with very little progress to show for our time. Any input will be greatly appreciated.

Thanks