In that case, explain adoption of M-16.
The M16 exactly proves my point. It is a rifle, designed to have a soldier carry more ammo than the M14 for the same weight, and has vitrually no similarities to the StG44.
I should be the one asking you to explain the adoption of M-16, which completely contradicts your ideas.
2 millions is extremely little for a battle rifle used in 90 countries during 50 years. You should probably explain why it is so underused.
Hardly underused. 2million is the number produced by FN. All the various derivatives such as the British one, for example are not part of the count. Overall in the world, FN and derivatves are second only to the AK and derivatives.
Kurtz cartridge allowed to have better accuracy then SMG round, while having reasonable recoil.
1. Kurtz accuracy is enough for WW2 weapon that is not sniper rifle.
2. STG44 was shorted and more handy in close combat then K98 or G43.
3. 5.56 rounds were developed because 7.62 round was not good for burst-fining due to having too much recoil.
4. 5.56 ARs were shorter and better suited for mechanized warfare and usage in viechles.
5. Interestingly, how much does a weapon of person that is carried by APC weights is fairly irrelevant.
I think similarities are obvious.
1. And post war NATO modern rifles could be easily converted to "designated marksman" weapons, which was big advantage. The USSR had to develop the SVD with different round to fill in that gap.
2. And the allied post war doctrine discouraged close combat, saying it does not allow the soldiers to use their advantages on the battlefield, so the was not an advantage. Automatic fire isn't even an option for most modern rifles, nor do soldiers train for it.
3. Which was one of reasons. The other, even more important one was the ability to carry more ammo for a firefight. The Kurz cartridge was much heavier than 5.56, and closer to rile cartridges in weight
4. Ehm, you do know soldiers don't use weapons inside the vehicles? They disembark to fight. It was a theoretical option on some soviet AVFs, but in practice trying to hit something out of a moving vehicle through a small firing port is exceedingly difficult. And in any case, cold war AVFs had little armor, so a single shot from an RPG could take out a whole squad if they were to stay inside their vehicle in combat.
5. And, interestingly, the armies in the world thought otherwise, and took great measures to reduce weapon weight. Mainly for the reasons outlined above - the APC carries a soldier to the battlefield, but once there, he has to move on his 2 feet.
Also, go ahead and explain why did US army created M4 carabine, that has shorted barrel and lower mussle velocity while having the same bullet as M-16.
You can't seriously be claiming a weapon developed in the 90-s for a completely different war, on a different technological level had anything to do with a WW2 weapon that was rejected after the the war.