Rubber bullets were trialled on sheep just weeks before they were used on the streets in Northern Ireland during the 1970s, a coroner's court has been told.
Baton rounds were rushed out to soldiers in Belfast and Londonderry even though testing was incomplete and no consideration had been given to the harm they could cause young children, it was revealed.
Fiona Doherty QC, representing the family of a schoolboy killed by a military projectile in April 1972, said: "This was a political decision.
"The urgency for the introduction of these weapons meant that the testing before they were introduced was limited.
"The experimentation testing was piecemeal."
Eleven-year-old Francis Rowntree died on April 22 1972 - two days after he was struck on the head by a rubber bullet while walking through the Divis Flats complex close to Belfast's Falls Road.
The case is mired in controversy with disputed claims on whether the boy was hit directly or injured by a ricochet, and if the bullet had been doctored to make it potentially cause more harm.
A Ministry of Defence (MoD) weapons expert told the boy's inquest baton rounds had been introduced in July 1970 to deal with riots.
According to Alan Hepper, the kind most commonly used in April 1972 was 1.49 centimetres long and fired with 55 grains of gunpowder at a speed of 73 metres a second (160 miles an hour), most likely from a Federal Riot Gun.
He said: "It (the baton round) was got into service because of a lack of capability.
"They needed something between the baton and bullet or CS and live rounds - to provide distance and have an effect on rioting people."
Pre-deployment tests included firing at the abdomen and thorax of adult sheep weighing between 10 and 14 stones but no specific assessment was done to establish the damage they could cause to children or young people, the cout was told.
Responding to an assertion from the Rowntree family barrister that development of the weapon was a work in progress, Mr Hepper replied: "It was an attempt to fill a capability gap."
Although it was stipulated baton rounds should only be fired at lower limbs and aimed to ricochet off the ground, there was no evidence this advice was passed down to soldiers on the ground.
"I saw nothing related to the soldiers being issued (with advice) or trained," added Mr Hepper.
The rank and file were also not told rubber bullets could kill, blind or seriously injure major organs.
Throughout 1972 - one of the most turbulent years of the Troubles - some 23,363 rubber bullets were fired and by December of that year the Army acknowledged they could cause very serious injury.
The court also heard that doctors at Belfast's Royal Victoria Hospital recorded 80% of injuries resulting from baton rounds were to the head and neck.
Some 67% of those hit were men with 64% of them aged between 10 and 19 years old.
Ms Doherty said documents showed efforts were made to prevent publication of the consultants' findings at the time.
An adviser to the General Officer Commanding, the most senior soldier serving in Northern Ireland, raised concerns about adverse press coverage during a visit to the hospital, the lawyer said.
The military also did not want to highlight the disadvantages of baton rounds, it was claimed.
Earlier the inquest was told that the soldier who fired a rubber bullet was too ill to give evidence.
The soldier, whose identity is protected and is known only as Soldier B, was taken to hospital on Wednesday and is undergoing further assessment, according to a barrister for the MoD.
He had been due to give evidence via videolink from an unspecified location.
Martin Wolfe QC said: "It is the case that Soldier B has presented every morning he was scheduled at the point in place where he was supposed to give evidence.
"He was required to leave the place as a matter of urgency and attended at hospital. He has well diagnosed and properly defined conditions.
"He returned home very late last night at about 11pm. He has yet to be seen by his family doctor. We will make every effort that proper medical evidence is before you to vouch for what has been said."
Ms Doherty said the Rowntree family were disappointed but looked forward to hearing evidence at a later date.
"Obviously it is disappointing that we are not going to hear evidence from Soldier B as planned, but we look forward to hearing that he has recovered and will be fit to return to give evidence in due course," she said.
Judge Brian Sherrard, who is presiding over the high profile inquest, described the situation as unfortunate and requested the production of medical evidence.
The coroner said: "It is unfortunate that we find ourselves in this position but we are dealing with relatively elderly people with pre-existing medical conditions; these things happen from time to time."
The hearing has been adjourned until Friday.