The offender was sentenced following a plea of guilty to 1 count of attempting to possess a commercial quantity of an unlawfully imported border controlled drug contrary to ss 307.5(1) and 11.1(1) of the Commonwealth Criminal Code. An additional drug possession offence was taken into account under s 16BA. Offending related to 5,366.79 grams of pure methamphetamine. Original sentence imposed 6 years imprisonment with a non-parole period of 4 years and 3 months. The offender appealed on the grounds that the sentencing judge failed to properly consider the ratio of the non-parole period to the head sentence, and that the original sentence was manifestly excessive. Non-Parole Period: Offender points out that the proportion of the sentence that is custodial is 71%, a proportion which, it is argued, is inconsistent with convention in Commonwealth matters where the non-parole period ordinarily represents between 60 and 66% of the total sentence. There is no such convention, and the sentence judge cannot be in error for failing to apply a rule of practice that does not exist. In determining the sentence to be imposed, and the portion of the sentence to be served as a minimum term, the sentencing judge considered all of those matters referred to in s 16A(2) to arrive at a sentence as required by s 16A(1). There was no error in the determination of the non-parole period. Manifest Excess: Offender contends that the sentence imposed is so far outside the available range of sentence that there must have been some misapplication of principle. The total weight of the drug involved was in excess of 5 kilograms of methamphetamine. Although offender did not play a senior role, they were a trusted participant in an operation directed at the acquisition of significant quantities of a border controlled drug. Serious offending was involved. The sentencing judge have attention to all relevant aspects of the matter, giving the applicant the benefit of a number of mitigating conclusions. However, the sentence had to comprehend principles of general and specific deterrence and was bound to be one that was proportionate to the gravity of serious drug offending. Noting those features, the sentence imposed does not, of itself, point to some error having occurred. The small number of cases referred to by offender do not establish a range of sentences indicative of error in this instance. Leave to appeal on ground 2 granted but leave otherwise refused. Appeal dismissed.