U.S Navy and Air Force tactical aircraft operating over North Vietnam in the early stages of the involvement in the South East Asian conflict in the mid-to-late 1960s faced an ever-increasing array of Soviet/Chicom-supplied air defenses ranging from eyeball-guided 12.7mm Dshk guns to the latest S75/SA-2 SAMs manned under the eye of Western experts and everything in between.
Some young aircrews even had to brave weapons their forerunners had to dodge over Western Europe in 1942-45. Specifically, among the Communist military aid delivered to Hanoi was at least 70 former German Luftwaffe/Wehrmacht 88mm Flugabwehrkanone delivered to the NVA in the mid-1950s from Moscow.
The big 88s were delivered alongside boatloads of MG42 machine guns, Kar98K Mausers, MP40 submachine guns, and Walther P-38 pistols, which came with millions of rounds of 7.92mm and 9mm ammo, all complete with funny little dirty bird markings.
For American forces facing VC irregulars and NVA regulars on the ground, 1965 seemed a lot like 1945 in some ways, with former vintage Soviet, Japanese, and French small arms often captured in secondary amounts when compared to Warsaw Pact-supplied German trophies from WWII.
New-made Chinese Type 56 AKs didn’t become the standard until the war matured.