The State of Victoria took ownership of the guns at the time of Australian Federation in 1901. In about 1901/1902 the Garrison Battery was converted to the Warrnambool Battery of the Australian Field Artillery (No 4 Field Battery) and equipped with four 7-inch naval guns mounted on field carriages. They were now a mobile unit but continued to use the Warrnambool Garrison area at Flagstaff Hill for practice.
The fortifications were declared obsolete in 1910, and work of dismantling the guns and relocating them to Cannon Hill commenced. The guns had previously been presented to the council by the Defence Department on the proviso that the cost of relocation be borne by the council.
All that was left was a shed, variously called the ‘General Store’ or ‘Armoury’. The shed appeared in numerous photographs of the time and seems to have been on its present site when the fortifications were operational.