I think I've read that 'caliber' is formally defined as 'hundredths of an inch', as in "45 caliber". If so, then "84mm caliber" would indeed be confusing (and incorrect ;^)...
9 posted on 01/17/2023 2:09:49 PM PST by Who is John Galt?
("...mit Pulver und Blei, Die Gedanken sind frei!")