Wow. GIs were literally spraying and praying with their grease guns.
My guess is that various rural police departments just kept "stuff that works" since it was not used that often. Same happened here, only in the mid did a police ditch Beretta and Thompson SMGs (M56s lasted until early 2000), even if MP-5s were available since early '80s at least.
MP5s were expensive, especially compared to 9mm blowback SMG already in the armoury. does the swedish police still use ksp m/45 with aimpoints? In the end the blowback guns are all pretty similar and even a brand new B&T blowback is not that much different from a surplus "carl gustaf" with aimpoint and torch mounted. Now I want a Beretta Mosccetto Automatic Beretta Modelo 938 with a rail welded on top for a red dot.
But the point my thoughts are circling around is, that there is a hole between M1 carbine wearing out and them needning replacement and the widepsread use of the MP5 (and then later short 556 guns). From personal experience a MP5 can easily hit tennisballs at 25 & 50 m. And considereing that most M1 have horrible sights according to Hackathorn and tus n ot hitting much the MP5 was better. Also reliable magazines. But ballistically .30 Carbine cartridge offers a bit more power than 9 Para, but keeping a similarly small size. The FBI had gone to the 10mm MP5 to get more power while staying with the compact package as well. (which had its own issues)
wikipedia has ~700 J for 9 Para and 1300 J for .30 carbine. (best millimetre has ~1000 J) So there is certainly more power there. Okay the 1300 J are from an 18" barrel. But still.
But nobody seems to have really bothered to design a new gun around the cartridge. Okay and then the eMbassy in London with the masked SAS and MP5 happened and then everyone wanted H&K I guess.
Edited by Panzermann, 21 May 2018 - 1025 AM.