Veterans of the Battle of Long Tan say their campaign for better recognition of their achievements is about to come to an end.

Key points: Just over 100 Australian soldiers from D Company 6RAR held off 2,000 Viet Cong troops on 18th August 1966

Just over 100 Australian soldiers from D Company 6RAR held off 2,000 Viet Cong troops on 18th August 1966 17 Australian soldiers lost their lives

17 Australian soldiers lost their lives 20 soldiers were recommended for bravery awards after the battle but that was cut to 8 by officials in Canberra

20 soldiers were recommended for bravery awards after the battle but that was cut to 8 by officials in Canberra D Company commander, Harry Smitth, has been campaigning for greater recognition of the actions of soldiers in the battle

A Defence tribunal is expected to hand down its decision on whether to grant additional gallantry awards before the battle's 50th anniversary on August 18.

"This is the last roll of the dice," says Ian Campbell, who is one of 13 soldiers who were denied a recommended gallantry award back in 1966.

Leading the fight for additional honours is the commander of the Long Tan company, Harry Smith, who was awarded the Star of Gallantry.

"People said to me I should let it go," he told 7.30.

"But to me, I wasn't the hero, my soldiers were the heroes."

'I said to myself, I'm still alive - I don't believe it'

Harry Smith, commander of D Company at Long Tan, has been campaigning for greater recognition of the bravery of his soldiers for decades.

The Battle at Long Tan in a rubber plantation in Phuoc Tuy province, South Vietnam, could have been an Australian military disaster.

Just over 100 soldiers were isolated, low on ammunition and outnumbered by Viet Cong and North Vietnamese Army (NVA) soldiers 20 to 1.

But against the odds, the men of D Company 6RAR, with the help of heavy artillery support, won the day.

"I must admit it was only after we got out of the battlefield at midnight, I was sitting in the back of an APC I said to myself, I'm still alive - I don't believe it," Harry Smith recalls.

The full extent of D Company's military achievement wasn't realised until the day after the battle.

"I couldn't believe the number of enemy bodies that were there," says Harry Smith.

"It was like a gigantic mixing machine that cut all their bodies in pieces, the artillery fire that landed on them."

In the three hours of close combat and artillery bombardment, 17 Australian soldiers lost their lives. The Viet Cong and NVA lost hundreds.

"The victory at Long Tan was important strategically," says historian Ernie Chamberlain.

"A boost to the Americans because it was the biggest victory to date, that is August of 1966, in South Vietnam."

Number of recommendations for bravery honours cut from 20 to 8

Harry Smith arguing for more recognition of the soldiers who fought in the battle of Long Tan.

But in the weeks after the battle, Harry Smith felt cheated.

His initial list of 20 recommendations for bravery honours — in a war that was becoming increasingly unpopular back in Australia — was cut back to 8.

Some of the men were awarded South Vietnamese honours, but under the policy at the time they couldn't be accepted and instead they were given dolls and cigar boxes.

"I said to Colonel Townsend, this is a ridiculous situation," Harry Smith recalls.

"He said there's nothing you can do about it, Smith, the awards are secret and it's a 30 years secrecy period — it was all done at a higher level."

That higher level, according to historian Ernie Chamberlain, involved officials in Canberra.

"A decision was made ... that the conflict in Vietnam in 1966 was not as intense as the conflict had been in Korea," he explains.

"So the scale, the ratio of medals was cut almost in half."

But Harry Smith was patient.

In the 1990s he began a process that led to several awards being upgraded in 2008, and culminated in a special Defence hearing last year into why 13 Long Tan soldiers had been refused gallantry awards.

Call for VC for Jack Kirby

Harry Smith wants the distinguished conduct medal awarded to former member of D company, Jack Kirby, upgraded to a Victoria Cross for his courage during the Battle of Long Tan. ( Supplied: Australian War Memorial )

One of the most contentious cases is that of Sergeant Major Jack Kirby. He was awarded a Distinguished Conduct Medal, but Harry Smith wants it upgraded to a Victoria Cross.

"When the enemy were assaulting in suicidal waves, Jack Kirby moved around the battlefield without regard to his own safety," Harry Smith recalls.

"His main job in action was to distribute ammunition."

Jack Kirby was killed in an artillery accident several months after the Battle of Long Tan, and his widow Bev Knight appreciates Harry Smith's efforts.

"I just admire that man for his continual drive, his resilience to hang in there, when it would have been so easy to give up," she said.

"Whether it's to be or not to be, I don't know. But Harry will be able to go to his grave knowing he did the very best he could.

"I hope for Jack's sake it can come through because he was pretty special, he really was special, and you never forget it, and it never dulls."