ΔE 38.2, loose: different enough that you should pick on purpose. Heavy Armour is noticeably darker, much more muted than Brazen Copper.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 38). Heavy Armour is noticeably darker, much more muted than Brazen Copper.
The same difference applies the other way round: Brazen Copper is noticeably lighter, much more saturated.
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 Brazen Copper on the colour wheel See Heavy Armour on the colour wheel
All matches: Brazen Copper equivalents · Heavy Armour equivalents