ΔE 7.1, close: similar, with a visible difference side by side. Leather Brown is a little darker than Matt Chocolate Brown. They are different kinds of paint: AMMO by Mig Matt Chocolate Brown is an ink, glaze or transparent paint and Army Painter Leather Brown is an opaque base/layer paint, so they won’t behave the same on the model even where the colour is close.
Usually, if you are not matching paint already on the model. Close match (ΔE 7). Leather Brown is a little darker than Matt Chocolate Brown. They are different kinds of paint.
The same difference applies the other way round: Matt Chocolate 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 Matt Chocolate Brown on the colour wheel See Leather Brown on the colour wheel
All matches: Matt Chocolate Brown equivalents · Leather Brown equivalents