appeal against sentence — importing a commercial quantity of a border controlled drug offence contrary to s 307.1(1) of the Commonwealth Criminal Code — offence relates to 23.7kg of pure methamphetamine — original sentence imposed 13 years’ imprisonment, with a 9 year and 6 month non-parole period — nature and circumstances of the offence — the nature, quantity, purity, source and value of the drugs concerned are highly relevant to assessing the objective seriousness of federal drug offences — necessary to bear in mind that often those involved in drug importation will know nothing about what they are dealing with except that it is a quantity of an illicit substance — it follows there will be many cases where a sentencing judge will be more concerned to identify the level of offender’s criminality by looking to state of offender’s knowledge about importation in which they were involved — leave to appeal refused — appeal dismissed