Hello Peter:
Just a note about my past experiences drilling holes in timber
For holes 2" diameters up we used a 3|4" skill drill with an auxiliary 3\4" pipe extension that was about 16" long. This was necessary so that a second person could help control the torque of the drill especially in oak or other hard wood. This was an older model skill, and even the 1\2" was more than one man could control in tough going. I have seen these drills get away and wind up (quickly) the unwary operator.
Even when the trigger is released the drill will continue to revolve, and can cause injury to the operator-Be careful and use a pipe extension at all times
NH