I agree with that as well Nick, nd to be honest, I think that the 600M carry on is a bit too far, because on the TV programme that I remember the historian speaking on about the shot, mentioned the the gate house is about200 yards away, which to me seems more achievale than 600M
It would be interesting to visit the grave and the Kirklees Abbey gatehouse to get an idea of the exact distance, to see if the shot could/couldn't have been possible to make
Willie