ΔE 37.9, loose: different enough that you should pick on purpose. Shell Shocked is a little darker, more saturated, cooler than Brazen Copper.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 38). Shell Shocked is a little darker, more saturated, cooler than Brazen Copper.
The same difference applies the other way round: Brazen Copper is a little 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 Brazen Copper on the colour wheel See Shell Shocked on the colour wheel
All matches: Brazen Copper equivalents · Shell Shocked equivalents