ΔE 9.1, close: similar, with a visible difference side by side. USAF Tan is a little lighter, more saturated, warmer than Australian Camouflage Brown.
Usually, if you are not matching paint already on the model. Close match (ΔE 9). USAF Tan is a little lighter, more saturated, warmer than Australian Camouflage Brown.
The same difference applies the other way round: Australian Camouflage Brown is a little darker, more muted, cooler.
ΔE is the colour difference between our two swatch estimates: under about 6 is close, over about 15 is loose. Real paints also differ in finish, coverage and how they thin, so test before you commit.
See Australian Camouflage Brown on the colour wheel See USAF Tan on the colour wheel
All matches: Australian Camouflage Brown equivalents · USAF Tan equivalents