"the .30 Lugar was developed after WWI as the various makers in Weimar Germany were prevented from making military ammo and they necked down the 9mm to .30."
Not even close.
The 7.65x21mm Luger cartridge was introduced as the ORIGINAL cartridge for the Luger semi-auto in 1898.
The new handgun and cartridge were offered to the German Army and Navy.
IIRC it was the German Army that liked the gun but wanted a larger cartridge with a heavier bullet. Luger blew the case shoulder out, shortened it by 2mm, and voila, the 9mm Luger was born in 1902.
In 1904 the German Navy adopted the new round and gun, and in 1906 the German Army followed.
And, finally, the Luger in 9mm remained in production during the Weimar years. The Treaty of Versailles allowed a 100,000 man German Army and a small Navy for whom arms and ammunition could be, and were, manufactured domestically.
"The gift which I am sending you is called a dog, and is in fact the most precious and valuable possession of mankind" -Theodorus Gaza
Baby Jesus cries when the fat redneck doesn't have military-grade firepower.