The public inquiry, expected to begin on 27 September, 1999, aims to find out why British soldiers in Londonderry fired on a crowd of civilians.

Lord Saville: Inquiry chairman

On 30 January 1972, 14 unarmed Catholic civilians were shot dead but the British Army has always maintained troops were responding to fire from paramilitary terrorists.

The demonstration of firearms, at an army firing range in the Lincolnshire countryside, allowed the inquiry team to hear weapons used by the British Army and those thought to have been held by paramilitaries at the time.

After the live firing exercise Greg McCartney, a lawyer for the victims' families, said: "I think today has been useful to distinguish between the different weapons.

"We do, however, have reservations about the way this was carried out because this is not a built-up area which Londonderry was."

He said those acting for the families would reserve judgement on the demonstration until audio tapes of the event had been analysed.

The Bloody Sunday inquiry is regarded as a symbolic move away from the Lord Widgery inquiry which took place soon after the killings. He found that the soldiers had been fired at first and that the people killed had been marching illegally.

The report was widely condemned for being inconsistent and lacking the testimony of eyewitnesses, many of whom were never called to give evidence.

This latest investigation is chaired by Lord Saville and includes on its board a former New Zealand judge, Sir Edward Somers, and the former chief justice of New Brunswick in Canada, William Hoyt.