Re-using lag bolt holes?
The important thing when reusing holes for lag bolts (or screws in general) in a material that the screw will cut threads in (i.e. wood, but also applies more generally to any material much softer than the screw being driven) is to turn the bolt backwards (counterclockwise for a normal right hand thread) until you feel it "drop in" to the existing thread - then start turning forwards. That way you are following the existing thread in the wood to reinstall the screw, not starting to cut a new thread just a bit off from that one and reducing the strength &amp; holding power of the wood.