Ya, the one in the photo is an early variant, milled. However, the Soviets always wanted an all-stamped receiver from the beginning of its inceptual phase to cut down on costs and simply construction. It wasn't easy to get right, so as a compromise until they got the stamping technique right, the first prototype and early production models were milled. Very few of these were produced in any significant number as they were still considered prototypical. Soviet military procurement was big on pushing out anything that worked first and foremost, then incrementally upgrading. By the mid-50s, the all stamped, strengthened AKM was in full production, replacing the milled AK-47s, especially as the latter was no longer compatible with other equipment. Subsequent AKs, like the 74, were all stamped and continue to be to this day.
I thought the cutout above the mag well meant this was a milled model?
Ya, the one in the photo is an early variant, milled. However, the Soviets always wanted an all-stamped receiver from the beginning of its inceptual phase to cut down on costs and simply construction. It wasn't easy to get right, so as a compromise until they got the stamping technique right, the first prototype and early production models were milled. Very few of these were produced in any significant number as they were still considered prototypical. Soviet military procurement was big on pushing out anything that worked first and foremost, then incrementally upgrading. By the mid-50s, the all stamped, strengthened AKM was in full production, replacing the milled AK-47s, especially as the latter was no longer compatible with other equipment. Subsequent AKs, like the 74, were all stamped and continue to be to this day.