It's first versions were full auto but in 1927 Thompson came out with the 1927a1 which was a semiauto version. The 1928 model (FA) had the foregrip changed to a more conventional flat style rather than the pistol grip type shown. The military adopted the flat grip style and used them extensively throught WW2, into Korea. The M3 'greasegun' pretty much replaced the Tommy towards the end of WW2. It was much lighter and cheaper to make than the Tommy.
The Thompson is still made by Auto Ornance, although AO is now under the ownership of Kahr Arms.
It is a heavy gun, 13.8 lbs empty and can accomodate either a 30 round stick mag or the more identifiable round 50 or 100 round drums. AO now makes a 10 round drum to satisfy some of our more socialist states. Being so heavy it has very little recoil from it's .45 cal ammo.
It's a real blast to shoot.
My 1927a1 Thompson:
