ΔE 10.7, fair: the same colour family, but not a straight swap. Primer Black Brown is a little lighter, more saturated than Matt Black Primer.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 11). Primer Black Brown is a little lighter, more saturated than Matt Black Primer.
The same difference applies the other way round: Matt Black Primer is a little darker, more muted.
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 Black Primer on the colour wheel See Primer Black Brown on the colour wheel
All matches: Matt Black Primer equivalents · Primer Black Brown equivalents