I am trying to discover some information about the odd French PDW of the late 1980s, the GIAT ADR (Armes de Défense Rapprochée). It had two pistol grips, one at the back and one at the front, complete with two triggers. The project was cancelled in favour of the FN P90 when FN was acquired by GIAT.
Internet sources indicate that it was chambered in a shortened 5.56x45 case, but the case length given varies between 22mm and 25mm. Some sources also say that the case was based on the 7.65x21 (.30 Luger), necked down - the case diameter is the same but the Luger case would be less strong.
Can anyone provide the correct information about the cartridge, and also the bullet weight and muzzle velocity, if possible?