THAT SHOULD TELL YOU SOMETHING, as the GALIL AK's, F.E.G.'s from Hungary, Arsenal of Bulgaria, and Russian AK's were all tested against the Chinese Norinco, and the Norinco came out on top as the most rugged, and best value DUE TO THE USE OF THICKER 1.5MM STAMPED CHINESE RECEIVERS, DOUBLE-HOOK TRIGGERS FOR SMOOTHER TRIGGER-PULL, and thicker Chinese barrels, despite the fact that it would have been easier for Finland and the U. S. Navy Seals to buy AK-47 variants from other Eastern European, or Russian sources.
Finally, Norinco of China, Zastava of Yugoslavia, and Valmet/Sako of Finland all use at least 1.5mm steel for their stamped receivers on their AK variants, thus eliminating the need for "mickey-mouse" anti-trip devices (band-aid that does not solve the problem of too thin receivers) found in the trigger groups of thinner 1mm steel receivers of Warsaw-Pact AKM's.
AKM is the Russian term of: Avtomat Kalashnikova Modernizya , which means modernized AK-47, referring to the stamped AKM versus the milled AK-47 of 1947.
Warsaw-Pact AKM's include: Soviet/Russian mfg.,F.E.G. of Hungary (SA-85's, etc.), and Romanian W.U.M.-1's, W.U.M.-2's, S.A.R.1, S.A.R.2, S.A.R. 3's, as well as Maadi AKM's, RML, RPM, and the MISR-90.
What does receiver thickness and the lack of "mickey-mouse" anti-trip device that only complicates your trigger group, mean to AKM performance???
Simple, if you only fire your thinner receiver AKM variants lightly, you usually won't have any problems.
But if you need more out of your AK, like sustained fire/rapid fire, like with 75, or 100 round drums, or with other "extreme situations", the thicker 1.5mm stamped receivers found in Norinco, Valmet/Sako, and Zastava/Serbian rifles are more durable.
This means the thicker 1.5mm receiver AK's are a lot less likely to experience malfunctions like the thinner 1mm receiver AK's do, when the thicker receiver Chinese, Yugoslavian, or Valmet's get hot under rapid fire, sustained-fire situations, because there's less "fatigue", thus "flex" & jams, in the thicker 1.5mm steel receivers, than in the thinner-walled receivers of the Warsaw-Pact AKM-type rifles.