There isn't a lot of documentation on how reaming woodwind instruments works, and how you do it. Is there a specific method to making a smooth conical bore, like in that of an oboe? I've seen people use D-bits, but I don't understand how you can make a conical bore with that.
Thanks to the Internet, questions like this are easily answered. For example, info on clarinet :
2 When the manufacturer receives the billets, workers inspect the lot. Then skilled workers place the billets on a borer, which drills a hole lengthwise through the center of each piece. The diameter and shape of this hole, called the bore of the clarinet, is crucial to determining the tone of the instrument. The bore may be drilled in a straight cylinder, or the cylinder may be slightly tapered. After the bore is drilled, the body pieces are turned on a lathe. The rectangular billets become smooth, round, hollow cylinders. These cylinders are then seasoned again.
There are some YouTube videos showing oboe-reaming in a machine shop.