Defence Forces of New South Wales – Part 1, 1854-1869
1st Regiment of New South Wales Rifles

Australian War Memorial. No makers mark. 1854-1859
See https://www.awm.gov.au/collection/C245922
Apart from short lived volunteer associations in 1804-9 that helped to quell the Irish convict rebellion, this was the first government enacted Volunteer Force, developed in 1854.

Evening News (Sydney), 27th June 1903 page 3.

Illustration from 1857 from The Australian picture pleasure book : illustrating the scenery, architecture, historical events, natural history, public characters &c., of Australia / engraved, selected and arranged by Walter G. Mason: “A groupe [sic] of officers of the Sydney Volunteer Rifle Corps”.
In the beginning, the quality of the officers was a problem as some had no previous military experience. Late, examinations would be required to be an officer. Inadequate drill attendance, absconding and resignations were also a problem. Uniforms were not supplied by the government, and could be expensive. As also happened in England, this forced some volunteers to leave when their uniform wore out, and prevented others from volunteering in the first place. When the perceived Russian threat passed in 1856, the legislature declined to vote for funds for the Volunteers.
In 1859 the volunteer Force was considered a failure, “moribund but not dead”. In 1860, a resurgence of interest (in light of the British troops heading for the the Maori Wars) lead to the formation of a number new corps. The 1st NSW Rifles were amalgamated with these new corps into the NSW Volunteer Rifle Corps.

This is meant to be a c.1855 NSW Volunteer Rifleman, but the colours of the uniform are wrong. The grey uniform was adopted in 1860, following the fashion set by British volunteers.
https://www.rnswr.com.au/wp-content/uploads/2015/07/THE-LINEAGE.pdf
See Cossum page 5.

The Sydney Mail and New South Wales Advertiser, 7th September 1904. “Parade of the First Regiment”