I too use music wire from Truvalue hardware stores. I take it that the temporary "L" shaped pins are bent w/ the heat from a torch.....otherwise music wire doesn't readily bend.
A 1/16 drill is used and if a new or properly sharpened drill is used, the fit of the hole/pin is a slight press fit. Later on, the fit is too tight after the finish has been applied and I use a 1/16" drill held in a hand vise to "ream" the hole.
I also drill straight through the wood and lug and have no problems w/ drill length.
Sometimes hardware store 1/16 drills have bent shanks and cause a lot of drill runout when spinning.
I use the full length when drilling and one can better see any misalignment of the drill w/ the dimple in the wood. A 1/16 drill used full length will move over if not exactly over the dimple and once a depth of 1/16" is cut, it's easy to align the drill for zero runout.
Some use a center drill which should be used when the workpiece is clamped like in a mill or lathe.
Drilling the holes in a stock can be a trying experience and judging from the amount of posts about drilling, many have trouble doing so.
Shown is my setup for drilling the bbl lug holes in one setup and the RR pipes in another setup. .....Fred
multiple photo upload