40-mm Guns M1, M1A1, M2, and M2A1: Precautionary Check of Breech Casing Top Cover Prior to Firing

VG- : A term used to denote a condition a slight grade lesser than VG. Very Good is defined by AB Bookman's Weekly as "a used book that does show some small signs of wear - but no tears - on either binding or paper. Any defects must be noted."