Ludwig Vorgrimler
Ludwig Vorgrimler (September 7, 1912 – February 23, 1983) is the man most commonly associated with the design of the Spanish roller-delayed CETME rifle, and its prolific offspring from the German gunmaker Heckler & Koch such as the G3, HK21, P9 and MP5. Early career with Mauser Born in Freiburg, Germany, Vorgrimler worked as an engineer for several arms manufacturers over his long career. He briefly worked for the Krupp factory from January to November, 1936. From there, he was recruited by Ott-Helmuth von Lossnitzer, the director of Mauser Werke's Weapons Research Institute and Weapons Development Group. He was assigned to Department 37, which was responsible for military small arms up to 15 mm in caliber and eventually led the sub-department in charge of aircraft weapon construction. During the Second World War the roller-delayed blowback firearm action was patented by Vorgrimler together with Wilhelm Stähle but the work was not entirely completed by the end of the war. Though appearing simple its development during World War II was a hard technical and personal effort, as German engineering, mathematical and other scientists had to work together on a like-it-or-not basis led by von Lossnitzer. Experiments showed roller-delayed blowback firearms exhibited bolt-bounce