This photo was taken during an inspection of invasion defenses near Hartlepool, on July 21, 1940. The interesting thing about this picture is that both the British and the Germans used it for propaganda purposes.

Nazi propaganda minister Goebbels saw the image as a godsend and used it extensively domestically, with the other Axis countries, and even in airdrops over Britain during the Battle of Britain with the text in English “WANTED” and at the bottom: “for incitement to MURDER.”

The gun is specially an M1928, with a 50 round drum.

This gun was standard issue for the US military at the time, and numerous guns of this type were provided to the UK through Lend-Lease.

Shortly before the US entered WW2, it began producing M1928A1, which had a simplified handguard, and eventually a simplified sight. The gun could still accept the gangster favored drums, but the military favored issuing stick magazines.

The M1928A1 was shortly replaced by the even more simplified M1 Thompson. The charging handle was moved from the top to the side, the muzzle was simplified, the sights were standardized as simple types. By 1942, Thompsons had been revised to M1A1s, with a host of simplifications as well as durability improvements. An M1A1 could be produced in half the production time as the old M1928A1.

Forgotten Weapons video on the M1928A1.

Forgotten Weapons video on the M1A1.

As the war went on, the Thompson would be increasingly supplanted by the M3 "Grease Gun". While the M3 lost out on style points against the Thompson, it was lighter and far faster and cheaper to produce than even the simplified M1A1.

The Thompson remained in limited use by the US military until the 1970s.

Wikipedia on Thompsons.

Task And Purpose article.