Issue was originally intended as G.I. Combat (DC, 1957 series) #222, as the title converted from bi-monthly to monthly frequency, but due to a clerical error in making the necessary changes in the UPC the contents were shifted to this series at the last moment (per The Comic Reader #181).
On sale date from the 1980 Library of Congress copyright records (
cocatalog.loc.gov). Date given as June 11 in Comic Reader #180 (listed as G.I. Combat #222).