ΔE 6.9, close: similar, with a visible difference side by side. Ammo Pouch Brown is a little darker, warmer than RAL 7027 Grau.
Usually, if you are not matching paint already on the model. Close match (ΔE 7). Ammo Pouch Brown is a little darker, warmer than RAL 7027 Grau.
The same difference applies the other way round: RAL 7027 Grau is a little lighter, 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 RAL 7027 Grau on the colour wheel See Ammo Pouch Brown on the colour wheel
All matches: RAL 7027 Grau equivalents · Ammo Pouch Brown equivalents