1. Drill first on lathe. If your off on your center hole it rarely matters, you lathe around them.
2. Harbor freights drill bit lathe morse taper 2 is 12.99 , and built for war, yes freight produced a solid product.. Rare
3. Drill with 6 inch bit, to start push bit in two inches, use 4 inch to drill both side pilot holes. Next pull bit out last 1.5 and lock her in, punch through remaining wood as needed.
4. Doing this method ive missed on about 2 in 100 from being lazy and pushing to fast, otherwise flawless
5. Im at about 25 seconds per thru-hole . Can it be done in less.. Yes, should it be, no your using a drill... Be safe its still a nasty hole in your hand if the plug shifts or you punch out the side...