My baseless opinion
the best SMG of WWII?
Id love to learn this by shooting each model and tender my results, as being Class III is somewhat out most folks's realm and mine, I have to back it up with facts.
the only full auto firearm Rex in OTZ has ever shot was a Colt's model m16A1HB at the range here (1995)
I was able to hold and look over a MP-40/I (43) during its cleaning buy that same class III owner of the Colt M16A2HB.
Ive read in Shotgun News the results of tests of WWII era SMG's and they ranked the Suomi tops in accuracy in short bursts of full auto.
I after years of reading this and that think the baddest WWII SMG just being so darn used, was the Soviet PPSh-41
PPSh factories were producing roughly 3,000 units a day. The PPSh-41 was a classic example of a design adapted for mass production (other examples of such wartime design were the M3 submachine gun, MP40 and the Sten). Its parts (excluding the barrel) could be produced by a relatively unskilled workforce with simple equipment available in an auto repair garage or tin shop
The PPSh-41 used 87 components, PPSh could be manufactured with 7.3 machining hours,Barrel production was often simplified by using barrels produced for the 7.62mm M1891 Mosin–Nagant rifle: the rifle barrel was cut in half, and two PPSh barrels were made from it after machining the chamber for the 7.62mm Soviet submachine gun cartridge.
Over 6 million PPSh submachine guns were produced by the end of WWII. The Soviets would often equip whole regiments and even entire divisions with the weapon, giving them unmatched short-range firepower.
Korean War
After WWII, the PPSh was supplied in large quantities to Soviet client states and communist guerrilla forces. The North Korean People's Army (NKPA) and the Chinese People's Volunteer Army (PVA) fighting in Korea received massive numbers of the PPSh-41, in addition to the North Korean Type 49 and the Chinese Type 50, which were licensed copies of the PPSh-41 with small mechanical revisions.
The dance of the PPSh-41 and the Thompson
WWII Military users of the Thompson M1928A1(1.7million mfg 1921 to present) had complaints about the "L" fifty round drum magazine; the British Army officially criticised "their excessive weight, the rattling sound they made...." and shipped thousands back to the U.S. in exchange for box magazines.
By the time of the Korean War, the Thompson had seen much use by the U.S. and South Korean military, even though Thompson had been replaced as standard issue by the M3/M3A1. With huge numbers of guns available in army ordnance arsenals, the Thompson remained classed as Limited Standard or Substitute Standard long after the standardization of the M3/M3A1. Many Thompsons were distributed to Chinese armed forces as military aid before the fall of Chiang Kai-Shek's government to Mao Zedong's Communist forces in 1949 during the Chinese Civil War. During the Korean War, American troops were surprised to encounter Chinese Communist troops heavily armed with Thompsons, especially during surprise night assaults. The gun's ability to deliver large quantities of short-range automatic assault fire proved very useful in both defense and assault during the early part of the conflict. Many of these weapons were captured and placed into service with American soldiers and Marines for the balance of the war.
The PPSh-41 was widely used during the entirety of the Korean War. Though relatively inaccurate, with a high rate of fire, the PPSh-41 was well-suited to the close-range firefights that typically occurred in that conflict, especially at night. U.N. forces in defensive outposts or on patrol often had trouble returning a sufficient volume of fire when attacked by companies of communist infantry armed with the PPSh-41. Some U.S. infantry officers ranked the PPSh-41 the best combat weapon of the war; while lacking the accuracy of the U.S. M1 Garand or M1 carbine, it provided more firepower at short distances. As one infantry captain stated: "on full automatic it sprayed a lot of bullets and most of the killing in Korea was done at very close ranges and it was done quickly - a matter of who responded faster. In situations like that it outclassed and outgunned what we had. A close-in patrol fight was over very quickly and usually we lost because of it."