In early November 1973, at a NATO workshop conference in Brussels West Germany was appointed to develop the 2nd generation (rifleman) rifle. H&K's new weapon was to be presented in sufficient numbers to NATO in April 1977. NATO wide testing would commence in 1977 with the goal of having a 2nd smaller caliber weapon alongside the 7.62×51mm NATO round rifle. West Germany wanted to have it ready by then. Then the caliber was changed to 4.3 mm delaying prototype development by months.