A Christchurch man accused of murdering another, after a night of partying, has told the court he didn't realise he'd fired a gun while the pair were fighting

James Arthur Holder is accused of murdering David Bridgwater - who was shot dead in Aranui in January last year.

The 55-year-old admits the shooting, but claims self-defence.

Open Justice reports the accused has given evidence in the third week of his trial, saying he was fighting with the alleged victim when a gun went off - but he didn't realise the shot had connected with the other man.

The Crown alleges he pulled the trigger in rage, and intended to kill him - or at least injure him - before callously leaving him to die.