MIMF

I've always used hanger bolts for my bolt ons threaded into a dowel installed in the neck heel as per Mario. I drill the block and neck on the drill press. Works well for me. I can't recall having to enlarge the holes for fit but it could be done if necessary. I dry fit the neck and mark with a centering punch of the right diameter then drill on the drill press. The block holes are drilled just the right diameter for furniture assembly nuts or whatever they are called.

This thread is scaring me away from ever trying a bolt on.

Don't be scared: it's possible to screw up anything. As Bismark said: "Any fool can learn from his mistakes; a wise man learns from the mistakes of others."

And if there's a way to screw it up, I'll find it.

I still use barrel nuts in the tenon so I made this jig for drilling the holes for the nuts, tenon and the mortise. For me it works better if I complete the neck set and then drill the holes for attaching.