I actually prefer drilling them myself. Using pre-drilled holes often requires splitting weights, whereas drilling the hole allows precise location of a single weight.
Use a #13 drill, and then a 3/16" ream to ensure a close tolerance fit for an AN3 bolt. Works well.
- RV10, Build in progress.
- RV12, N975G, "The Commuter"...many great hours and happy landings so far.
- Several others that are now just great memories for me.