Allan Wayne Jackson, 34, was sentenced by video link at Port Augusta Courts on Wednesday by Judge Kevin Nicholson for aggravated threatening life and for rape, committed on August 22, 2006.

Jackson had struck up a relationship with the female complainant, who was 15 years old at the time, and the male complainant, who was in his twenties.

The pair was staying in Jackson's home in Port Augusta while they were travelling, and would buy small quantities of cannabis from him.

On the night of the offences, people had gathered at the house where the complainants were staying to socialise.

Jackson arrived during the evening, and started arguing violently and aggressively with the man.

In evidence presented during Jackson's trial, it was suggested that this argument was over money that Jackson believed the two victims owed him for cannabis supplied to them on credit.

"On any analysis, the reason for the argument is irrelevant," Judge Nicholson said.

"Your behaviour was extraordinary."

Jackson followed the man into the bathroom, where he pulled out a cut-down gun, pointed it at his throat and said he was lucky he was not dead yet, and that he could kill both the victims and no one in the house would say anything.

Soon after, Jackson left the house and insisted that the girl go with him to his house where more of his friends were drinking and socialising.

She stayed with him in his house or in his car until the next morning, and Judge Nicholson said that for that time, she was under his effective control.

While the girl was in his house, he tried to persuade her to have sexual intercourse with him several times.

She made it plain she did not want to do this, but he forced her to have sex with him without her consent.

Judge Nicholson could not conclude beyond reasonable doubt that Jackson knew the girl's age.

Jackson had a number of offences on his criminal record, including a number of offences of dishonesty, drug-related offences and a number of motor vehicle and firearm offences.

Jackson has been in custody for the offences since January 23 last year, and spent two months and two days in custody before obtaining bail in 2006.

He was sentenced to three years' imprisonment for the assault, and five years' imprisonment for the rape, to be served consecutively, with a non-parole period of four years and nine months, backdated to January 28 and with three months' credit for time already spent in custody.