Our military sure loved it. The German military, well, not so much.
"By the time World War II began, stocks of shotguns were too small to support the mobilization and new orders were placed. The well regarded Winchester Model 12 trench and riot guns were again procured with a total of more than 80,000 guns ordered by the U.S. Government by 1945, more than any other combat shotgun of the time. Collectors will notice that there was a change in the ventilated heat shield during WW II from the WW I design of six rows of holes to only 4 rows starting in 1942."
http://olive-drab.com/od_other_firearms_shotgun_m12.php
