The SDK (Schalldämpfer Karabiner, "Silenced Carbine"), also known as the "Adolf Hitler assassination rifle", is a suppressed bolt-action rifle purportedly developed in Nazi Germany in 1939, although it is thought to have actually been a hoax produced after World War II.
The origin on the SDK rifle is disputed. It first came to public prominence in the late 1960s, when it was brought to the United States from Germany by Lt. Col. James Atwood, a US Army officer and Nazi memorabilia collector. Atwood claimed the rifle was commissioned in 1939 by Graf von Helldorff for the Gestapo, and that a sole example, marked serial No.2, was recovered from von Helldorff's home after the war. These claims were republished in several contemporaneous publications.
Atwood, however, was known for selling fake Nazi daggers and attaching falsified stories to them to drive up their value. This has led some to believe that Atwood also faked the rifle and invented the details about its invention and discovery. Contrary to Atwood's claims, it has been suggested that he actually commissioned a gunsmith in West Berlin to create the rifle so that he could sell it as an item of historical interest in the US.
Atwood sold the SDK rifle to a private collector in the early 1970s. It is not known what has since become of it.
The SDK appears to have been a bullpup design, with the bolt, breech, and magazine feed located in the stock of the weapon. The barrel ran along the entire length of the gun and was encased in a large integral suppressor. The SDK was outfitted with a scope and had a twin-trigger arrangement. The gun was fed by Luger magazines.
It was also reported that the SDK was chambered for soft-nosed, unmarked 9×19mm that were tipped with cyanide, although this was likely an embellishment by Atwood.
- Saga, April 1970
- Waffen Revue #20, 1976