ΔE 20.8, loose: different enough that you should pick on purpose. USAF Brown is noticeably darker, more muted, warmer than Bone Khaki.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 21). USAF Brown is noticeably darker, more muted, warmer than Bone Khaki.
The same difference applies the other way round: Bone Khaki is noticeably lighter, more saturated, 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 Bone Khaki on the colour wheel See USAF Brown on the colour wheel
All matches: Bone Khaki equivalents · USAF Brown equivalents