Experimental cartridge by Brenneke during the period 1937-1940 that ultimately lead to the development of the 7×66 Vom Hofe cartridge. This specimen was based on the 9.3×64 Brenneke case necked down to 7mm. This trial appears unsuccessful and no commercial production appears to have been carried out, although it is mentioned in a c1937-38 Brenneke catalogue. Originally thought to be the 7×64.5 Brenneke Maximum but the case dimensions are not the same. This was reclassified by Brad Dixon as the 7×64 DWM Experimental with reference W136