ΔE 15.1, loose: different enough that you should pick on purpose. Oxide Brown Medium is noticeably darker, more saturated, cooler than Ammo Pouch Brown.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 15). Oxide Brown Medium is noticeably darker, more saturated, cooler than Ammo Pouch Brown.
The same difference applies the other way round: Ammo Pouch Brown is noticeably lighter, more muted, warmer.
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 Ammo Pouch Brown on the colour wheel See Oxide Brown Medium on the colour wheel
All matches: Ammo Pouch Brown equivalents · Oxide Brown Medium equivalents