More carelessness on your part: I clearly stated that I do NOT have a crossbow. However, my kids have Nerf guns, but they are not powerful enough to propel objects across the parish boundary.
Is that Barham in Suffolk or Kent? Or a mistype of Barnham? If it's the Kent one, I can help as, if I had a crossbow, I could probably shoot an arrow into the parish of Barham from a south-facing window of my house. There's no way I could hit the Suffolk one, or Barnham though, so the OP's...