Formed in late 1942 from the machine gun companies of several infantry battalions, the 6th Machine Gun Battalion undertook training on the New South Wales south coast before being deployed to New Guinea where they took part in the Markham and Ramu Valley – Finisterre Range campaign, defending the airfield at Gusap, and undertaking patrols.

[6] With an authorised strength of 700 to 800 men, the battalion was equipped with 48 Vickers medium machine guns that were spread between four main companies.

While at Shellharbour, on 16 May 1943, the battalion took part in rescuing the crew of a US tanker, the Cities Service Boston, which sunk near Bass Point after running aground.

They were later commemorated in a memorial that was established in 1968 near the wreck site, and were also decorated posthumously by the United States for their efforts.

[8] The 6th Machine Gun Battalion came under the command of the 7th Division, in October 1943,[14] and, less one company which stayed in Port Moresby, it joined the Markham and Ramu Valley – Finisterre Range campaign.

Conditions around the airfield were highly malarial and the machine gunners were subjected to a number of aerial attacks.

[8] As personnel were evacuated due to illness, the Port Moresby company was used as a reinforcement pool until it was disbanded.