A Norwegian Army f**kup..
I the end of the 70'ies the Norwegian army and airforce used the P38/P1 and some P08 Lugers as their main handgun. It was discovered that the old stock of Raufoss 9mm ammo cracked the frames in the old guns. To remedy this they bought new mild loaded 9mm ammo from FFV in Sweden.
However, then it was discovered that using the new FFV ammo in Stenguns and MP38/40 had an interesting result. Uncontrolled mag dumps because the bolt in the subguns didn't travel far enough to the rear to reach the sear but far enough to pick up a new round from the magazine..
Remedy: "We cut the main spring!"
Result: The subguns worked as they should again with one exception. The mainspring was now too weak to close the bolt when shooting upwards. As Norway is a country with a lot of mountains this was obviously a major problem..
The army then realised that this was a major cockup. The result was that, I think, about 140000 Stens in storage were converted to nails.
Then they were the first army to convert to the Glock 17 ( I think even before Austria)
Then they ordered 40000 MP5 to replace the MP38s and MP40'ies mainly used in the National Guard.
And they ordered new 9mm+P ammo.
The mild FFV 9mm ammo was "dumped" to the sports shooters for one cent pr round. A lot of my pistol shooting buddies ended up with 30, 40 and even 50000 rounds.
Last note. A lot of the soldiers in the National Guard did not want a new MP5 instead of their old MP40. I think the main reason was cleaning.
The best argument against the MP40 to MP5 swap I heard was this. "The MP40 has a much better intimidation factor than the MP5. The MP5 has only killed a handfull of people in the hands of the SAS and GSG9. The MP40 has killed houndreds of thousands in the hands of the Gestapo not forgetting the house raids at 0400 with Gestapo agents wearing black leather coats!"
At the time the soldiers in the National Guard had their weapons and ammo at home in case of a Soviet invasion. Who today would not want to have a new selective fire MP5 under the bed for free
About 100000 NG soldiers had a G3 with ammo "under the bed" out of a population of only 4.5mill. Today there are app 40000 NG soldiers armed with HK416 and HK417DMR.