An short interesting article of some of the covert firearms and weapons produced by Britain's SOE during WWII and their use in history:
The Guns of Welwyn: Weapons of the British SOE - Spycraft 101
During WWII, British technicians and engineers developed an incredible variety of weapons and gadgets at Station IX located on the grounds of the Frythe Estate near Welwyn, England. Here are five of the unique weapons they developed for use behind enemy lines.
spycraft101.com