Haven't seen anything which explained just what the problem was the Soviets had with the stamped receivers of the original AK design. It may have been the stamping dies, or it may have been the type of steel they had. If they didn't have a big metal stamping industry, then they may not have been making the correct type of steel to use in stampings. They may also not have had the correct types of presses, for the same reason.Well, not so much a struggle as a complete trainwreck that necessitated an almost immediate (as far as Russian timescales go anyway) switch straight back to milled and machined receivers for their AKs which lasted several years until they got themselves some better German PoW machinists. (Other sources of skilled slave labour were available, check local listings for details, all rights reserved.)
I'm pretty sure that if we had pursued the new hotness of stamped receivers and other bits for the EM2, we would have run into the same trainwreck.
And thanks to the new Tory government and the American idiots who wanted a tarted-up .308 Remington calibre battle rifle, even if we had fixed all the problems with the stampings, it would still have been cancelled and we would have ended up with the FAL anyway.
The Germans were good at metal stamping because they produced a lot of toys, and toys of that era used a lot of stampings. Post WWII the automotive and appliance industries used a lot of stampings, and were the major driving forces behind the development of better steels, presses, and tooling for stampings.