BNE - SYD, VA were policing at Premium Entry again, my carry on was 5.5
On the return, with exactly same bag and contents was weighed by QF in SYD. My bag lost 400g and came in at 5.1
Scale calibrations much... (unsure who was right / closer to being right!)
What Diet is the bag on.... seriously though I weighed a bag in Mel QF terminal 5.5kg an hour or so later in Syd 6kg. I only had water on the flight. The scales vary from gate to gate and airport to airport.