ΔE 7.3, close: similar, with a visible difference side by side. Chainmail is a little lighter than Metallic Medium.
Usually, if you are not matching paint already on the model. Close match (ΔE 7). Chainmail is a little lighter than Metallic Medium.
The same difference applies the other way round: Metallic Medium is a little darker.
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 Metallic Medium on the colour wheel See Chainmail on the colour wheel
All matches: Metallic Medium equivalents · Chainmail equivalents