ΔE 6.6, close: similar, with a visible difference side by side. Deep Khaki Drill is a little darker than Australian Camouflage Brown.
Usually, if you are not matching paint already on the model. Close match (ΔE 7). Deep Khaki Drill is a little darker than Australian Camouflage Brown.
The same difference applies the other way round: Australian Camouflage Brown is a little lighter.
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 Deep Khaki Drill on the colour wheel
All matches: Australian Camouflage Brown equivalents · Deep Khaki Drill equivalents