There are several stories about these rounds. Here is one. Does anyone have any FACTS ?
This unique high velocity experimental cartridge was an early German-British effort. The case type (DWM 469A) was manufactured in Germany by DWM. The cartridges were loaded by the British firm STURTEVANT ENGINEERING On contract for the DEUTSCHE GEWEHR PRUFUNGS KOMMISSION ( GERMAN RIFLE EXAMINATION COMMISSION ) . This commission examined new rifles for possible use by the German military. This collection came with an envelope with this notation; " Bullets (5) 1 long round nose , 4 short " " , 1 long pointed - 5 MM STURDEVANT MADE BY GREENER ON DWM CASE # 469a - FROM VAL FORGETT COLUMBUS O. JULY 1964 " FORGETT bought a large part of the GREENER estate when it was sold in England.