Two Auckland trauma surgeons began an investigation after treating patients who had been shot in gang-related violence. Their study of high-powered air rifles involved shooting dead pigs - and now they want stricter laws for the weapons. 

WARNING: GRAPHIC IMAGE BELOW 

New Zealand trauma surgeons who treat gunshot victims tested easily-available air rifles and found they were potentially lethal from 10m. 

The two doctors now want the modern, spring-loaded weapons to be regulated in the same way as other firearms. 

Successive governments have been encouraged to crack down on high-powered air rifles. While some now require a licence, others can be purchased and used by anyone aged over 18. Photo / File 

A second, unpublished study also found that air rifles were responsible for a third of the gunshot injuries treated in Auckland City Hospital over a 10-year period and caused similar damage to a shotgun. 

Air guns were often thought of as children’s toys or beginner’s guns and unlikely to cause harm, said Dr Benjamin Black, a general surgeon and trauma fellow based at Auckland City Hospital. 

But research he was involved in showed that high-powered, unlicensed air guns had similar “lethality” to a .22 rifle, even at an intermediate distance. 

Dr Black and a colleague, Dr Kevin Peek, decided to investigate the weapons after treating several patients who had been caught up in gang violence. 

Air rifle injuries were typically accidental and often involved children. But the patients they dealt with were the victims of attempted homicide using an air gun. 

In a study published in the New Zealand Medical Journal today, the surgeons fired a spring-loaded air rifle at pig cadavers and ballistics gel, which are both routinely used to mimic human tissue. 

Black, who has a military background and hunts recreationally, shot into the pigs’ chests at a distance of five and 10 metres and then measured how far the pellets breached the animals’ chest walls and organs. He and his colleague then assessed how likely it was that those injuries could be lethal to a human. 

Out of five shots taken at the cadaver from 5m, two caused injuries which were likely to kill a person, two shots were potentially lethal, and one caused a non life-threatening injury. 

At 10m, there was one injury likely to be lethal, one potentially lethal injury, and three non life-threatening injuries. The chest wall was breached by a majority of the shots at both distances. 

The ballistics gel produced similar results. 

The spring-loaded air rifle used in the study had a "muzzle velocity" of 300m a second. Photo / NZMJ 

“We were expecting to see some pretty significant injuries,” Black said. “But we were surprised at how effective these were at 10m. If it was on target, it would cause a potentially lethal wound. And that is certainly quite concerning to us.” 

A yet-to-be-published study separately found that air rifles were responsible for 38 out of 114 firearm-related trauma injuries treated at Auckland City Hospital over a 10-year period. The exact model of air gun in these cases is not known. 

“In trauma, we use a scoring system called an injury severity score, which gives a ballpark of how bad the injuries were,” Black said. “And injuries with shotguns and air rifles were about the same in terms of the severity.” 

Pig carcass opened to show heart injury caused by air-rifle impact through the chest wall. Photo / Supplied 

Successive governments have periodically been told to treat high-powered as rifles as firearms under the law, including in a 1997 inquiry into gun control.  

Licensing requirements were introduced in 2011 for pre-charged pneumatic (PCP) air rifles after two fatal attacks, including the murder of Police Sergeant Don Wilkinson.  

But a licence is not required in New Zealand for purchasing or using air rifles which are CO2-powered or spring-loaded. 

“We’re very keen to be involved in increasing the regulation of [spring-loaded guns],” Black said. “It is fairly clear that these weapons are analogous to a .22 rifle, which are licensed. 

“So we think it’s reasonable that they think about licensing these weapons or decreasing the power of the guns that are able to be owned without a gun licence.” 

National and Act have committed to rewriting gun laws in New Zealand as part of their coalition agreement. 

Associate Minister of Justice (Firearms) Nicole McKee did not directly address the issue of air rifles in a statement to the Herald, saying only that a “robust” consultation process would take place and that public safety was a priority for her. 

Act MP and Associate Minister of Justice Nicole McKee is leading a review of firearms laws in New Zealand. Photo / Mark Mitchell 

Restricting the firearms would not affect recreational shooters, the authors of the paper said, but would potentially keep them out of the hands of unsuitable people. 

Some countries, including Australia and Singapore, treat air rifles the same as firearms under the law. 

Others, such as the UK and Canada, restrict air guns above a specific energy level or muzzle velocity. And 28 US states have various restrictions on air guns. 

The authors said air gun ownership in New Zealand had proliferated in recent years, with 130,000 imported between 2012 and 2016 — more than powdered rifle and shotgun imports. 

Although some were low-powered, like BB guns, the statistics underlined how many of the weapons were coming into the country, they said. 

The power and bullet mass of modern air rifles were also increasing. 

“As these weapons become more refined and other firearms become more restricted, it would be reasonable to assume that wounding with criminal intent may also become more common,” the authors said. 

The air gun used in the study was available for purchase at several gun retailers in New Zealand for between $600 and $900. 

The Gun City website said in its advertisement: “Ten shots, zero reloads, endless possibilities”. 

Isaac Davison is an Auckland-based reporter who covers health issues. He joined the Herald in 2008 and has previously covered the environment, politics, and social issues.