The MG 42's issues were more logistical. It was designed for an idealised situation (e.g. shooting range). Not as the article describes it "total war" where you

The MG 42's issues were more logistical. It was designed for an idealised situation (e.g. shooting range). Not as the article describes it "total war" where you have to carry everything you need to the battlefield. That meant issues like weight, complexity (for field repair), and replacements became a real headache. But the whole idea of the General Purpose Machine Gun (GPMG), which I'll note everybody adapted after WWII, was to make a lightweight "heavy" machine gun. No water cooled barrel, no requirement for a heavy tripod, in the light machine gun use case it was fired from a bipod, and could be put into use quickly. Those extra, quick change barrels were a feature, not a bug, such a German infantry unit was organized around the GPMG, one guy would carry it, others would carry spare barrels and ammo, their job was in part to keep the machine gun running and protected from the enemy. Issues like the high rate of fire were a tactical choice the Germans made, shared by no others to my memory (I believe the theory is that you would seldom have a good target for long, so you had to make the best of it while it existed). E.g. I see in the Wikipedia page that the post-WWII Austrian version has a much heavier bolt to reduce the rate of fire: https://en.wikipedia.org/wiki/MG_42 https://en.wikipedia.org/wiki/MG_42 And the Germans are still using it in the adapted for 7.62 NATO MG 3 variant. Accuracy is also a tradeoff, there are many modes of machine gun fire like plunging where you want a degree of dispersion. That said, yeah, feedback from the front is slow, can take a whole war to result in real changes. These things don't get put to the real test until real war; e.g. aside from the earliest M16s, none of these issues are a patch on the string of problems that initially crippled our Mark 14 torpedo used in WWII: https://en.wikipedia.org/wiki/Mark_14_torpedo https://en.wikipedia.org/wiki/Mark_14_torpedo