Some light lathes will bore a through hole in a workpiece with a slight bell mouth tape; my 12" Atlas does.

Turning the workpiece end for end in the chuck, using the largest boring bar that will clear the hole for the final cuts and using a spoon bit often result in a parallel bore…with the Atlas, anyway.

By the same token, it pays to buy the best lathe chuck you can find, keep it clean and properly lubed and keep your boring tool points honed between cuts.

If you don't have an accurate 3 jaw, you can use a 4 jaw independent chuck dialed in for the end for end operation.

A spoon bit looks somewhat like a workturner's gouge.  So, it's like a D-bit, but more like a C-bit (hence the "spoon" part of the name).  The bit has a rounded front that bores the hole, and its vertical flutes clean the hole's sides.  They cut regardless of the direction that you rotate them, making them practical for old reciprocating drills like bow-drills.  They are really old-school, predating twist drills.

I bought one of those enormous collections of stones for my Foredom flexible shaft tool to suppliment the collection of burrs that I bought with it.

When you have finished cutting and honing a D bit, you can convert it to a spoon bit by using a tapered stone to hollow it out. You will get very proficient at bringing the cut right up to the edges after a few tries, increasing cutting edge rake. In effect, this converts a reaming tool into a cutting tool…from enlarging a hole to initiating and self-reaming one. (WOW!)

Older literature (circa 1910's) shows these cutters in operation.

Lindsay's book "Tool Making 1905" shows a tangential tool holder identical to the one Tyler obtained recently. These were also illustrated in early 1900's editions of the Model Engineer. Sometimes, the older tooling is every bit as efficient as the latest.