Drive-by shootings intended to settle petty disputes and protect gangland turf have surged in Sydney but overall gun crime in NSW has halved since the 1990s, according to the latest figures.

A shooting in a public place occurred once every three days in Sydney last year with such incidents increasing by 143.9 per cent in the past 16 years.

But a report into long-term gun trends by the NSW Bureau of Crime Statistics and Research found that the total number of criminal incidents in the state involving a gun dropped by 48 per cent between 1995 and 2011.



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Gun murders, armed robbery and unlawfully discharged firearm offences all fell significantly while "discharge firearm into premises" type incidents rose from 41 in 1995 to 100 incidents in 2011, creating a puzzling trend for police and firearms experts.