How much does a 4x4x8 weight?
I weighed a few 4X4X8'.The pressure treated ground contact was between 25 and 30#.
The weight of 2X4X8 was 16 # each, so the 4X6 should weigh 32# with the same moisture content.
You can only estimate the weights to be "real heavy" because the wood has the largest variation.