User blog comment:Delta 4-7/WWII Weapons Project/@comment-1518024-20100514163502

The Sten was designed when after Dunkirk, Britain had lost a lot of equipment and needed to produce a cheap gun. So the Sten was made almost completely made of stamped metal. The Grease Gun was developed by the U.S.A when they saw the Stens and MP40s as a cheap alternative to the Thompson. However it was unpopular.