Here is an interesting Patrone 318 ammo chart. It is from april 1942.
Its interesting that barrel life was noted with 600 rounds. The steel case cartridges are more expensive than the brass ones.Steel cartridge comes for 1,30 Reichsmark and the brass cased cartridges for 1,10 RM. An average worker gets app. 70 RM monthly pay.
The chart say that no new guns where produced and tells the ammunition in stock.