Six British soldiers serving in Iraq were killed by the same Western-made rifle within three months last year, an inquest was told yesterday.

Rifleman Aaron Lincoln, 18, of the 2nd Battalion The Rifles, was the second victim of the gunman. A high-velocity 5.56mm round – the normal bullet fired by an American M16 or a British SA80 – penetrated Rifleman Lincoln’s protective glasses and helmet as he was on patrol in Basra on April 2 last year.

Ann Kiernan, of LGC Forensics, told the inquest at Spennymoor, Co Durham, that the bullet had been fired from the same gun that killed several other soldiers in the same area between March and June. She said that the bullets had been manufactured in the United States by Lake City Arsenal, an arms manufacturer.

Andrew Tweddle, the coroner, who recorded a narrative verdict of unlawful killing, said that Rifleman Lincoln had sustained a single gunshot wound to the head. “This 5.56mm, US-manufactured round was not fired by friendly forces,” he said.

Ministry of Defence officials said that the Iraqi gunman involved had not been using a special sniper rifle. They named four of the other victims as Kingsman Danny Wilson, 28, of the 2nd Battalion The Duke of Lancaster’s Regiment, who died on April 1 last year; Kingsman Alan Jones, 20, of the same regiment, who was killed on April 23; Rifleman Paul Donnachie, 18, of the 2nd Battalion The Rifles, shot dead on April 29; and Corporal Rodney Wilson, 30, of the 4th Battalion The Rifles, who died on June 7. Inquests have been held in all these cases. The sixth victim is believed to have been Corporal Jeremy Brookes, of the 4th Battalion The Rifles, who was killed on May 21.

A spokesman for the MoD said that the agency provided the best equipment, training and procedures to protect British troops. He added: “It is, however, difficult to protect personnel from all potential threats.”

Major Alexander Baring told the court that the danger to soldiers was substantial. “The threat in Basra city was a very heavy threat,” he said.

He said that all soldiers would have been wearing full body armour, as well as new helmets and goggles. However, the court was told that the Armed Forces had not been provided with helmets strong enough to withstand the type of high-velocity rifle that killed the victims.

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