Rod
What did I find? Well - that its mainly a work of translation and not of archery per se, that it contains inconsistencies with regards to some of the weights used ie that some measures are given as different weights in different parts of the text, and units of weight, when researched seem actually to be units of volume!
A comment from Stephen Selby on weight and volume when posed this question confirms what I first thought on reading this point.
In Ancient Chinese names of weights and volume can be synonymous since a given weight is derived from a certain volume of (in this case) water.
This should not be a concept foreign to anyone who knows that a Specific Gravity of one derives from 1 litre of water weighing 1 kg (leaving aside the refinement of specifying a temperature).
Rod.