Reamers are expensive. Check out Starrett, B&S, etc. For one-time or occasional use, I would recommend the General Sweep. The T-handle is detachable and the reamer body fits snugly on a cordless drill with a 1/2" chuck. It's sharp, cuts well, but you have to be careful with the drilling method. The base end of the reamer is 1/2 inch. an end that is the size of most acoustic guitar end studs, and the drill bit should be even and straight. Avoid swinging your arms and clean the flutes more often as the hole widens. Most guitar finishes add a bit of build up to prevent a clean, smooth tone. Cutting by hand takes some time and patience. I would recommend the General Sweep for any wood tapering/unrolling tasks, especially guitars.
Essential Trauma & Bandage Shears For Medical Professionals: Surviveware'S 7.5 Inch First Aid Scissors
43 Review
Smart electric grill Tefal Optigrill+ XL GC722D34
146 Review
Accusize Tools HSS Alignment Tool 0522-0012
3 Review
Cutting-Edge Reamer Machine: Unrivaled Precision and Efficiency with Straight Chucking Milling
3 Review