Grab that right now! If it's old enough to have corrosive primers, it probably has some collector value as an unopened can or individual boxes. That might even apply to later dated stuff.
Shooting it: The US decided to move away from corrosive primers in 1949, but that took some years to implement. See page 6 of this document, http://www.odcmp.org/1101/USGI.pdf , for "safe" head stamp dates.
Also note that the document says that while there was some steel cased .45ACP was used for the 1955 National Matches, all steel cased WWII US military .45ACP used corrosive primers.
Regards,
Greg