Just wanted to pass along that the Sieg bullpup rife was developed by U.S. Coast Guard Gunner’s Mate James Sieg. I don’t believe he was ever a commissioned officer. He did patent his compensator in Patent number: 2451514 Filing date: Nov 21, 1945 and Issue date: Oct 19, 1948. The American Rifleman article shown in the slide show comes from the April 1946 issue. The rifle is not in the collection of the American Firearms Museum. Sieg was listed as a Maryland inventor by the Enoch Pratt Free Library in Baltimore.
Just to clarify, by the American Firearms Museum, I meant the National Firearms Museum located in Alexandria, Virginia.
Looking at that compensator it seems to compose of an outer shell and a perforate barrel running through it. Is that thing rifled on the inside? And does the bullet actually touch its walls? Or is it just a tube of a larger caliber that it flies through?