The bolt is only used to hold the washers to space the parts while they are match drilled to the spar. Either drilled or un-drilled bolt will do.
If you read ahead you will see that after you match drill - you will disassemble and de-burr. Then rivet the parts in place. The bolt will not be used when you re-assemble it.
When you attach the aileron to the wing in section 38 it will be a longer bolt & the washers will be replaced by a bearing.
Did A-1207-L not come match drilled/final sized already? Mine was and I don’t remember putting a bolt in there since the holes to rivet were already final sized. Maybe I need to go back and throw a bolt/washers in there to see if vans predrilled holes correctly lined up that bolt hole. I noticed some pages of the plans in the emp and wing kit tell you to match drill parts that come already done for you.
Did A-1207-L not come match drilled/final sized already? Mine was and I don’t remember putting a bolt in there since the holes to rivet were already final sized. Maybe I need to go back and throw a bolt/washers in there to see if vans predrilled holes correctly lined up that bolt hole. I noticed some pages of the plans in the emp and wing kit tell you to match drill parts that come already done for you.
The kits are always evolving. The plans don’t always get updated immediately because it’s not an assembly critical detail, the builder gets to that step and finds it already done and just moves on to the next step.
The OP may be building from an older kit.