Today I went back to the range and scored 5 slick spine, steel, Chinese 30 round AK magazines, new in the wrappers. And a rough looking ribbed spine, steel AK magazine that has some rust on the outside of the mag body.
Paid twenty dollars each for the Chinese magazines, and got the unknown one for free
The unknown magazine was disassembled after the follower wouldn't go past a certain point.
So, as any good troubleshooter would do, I looked for the cause. Initially I thought it was the rust at the back of the tube causing the binding, but.......
Turns out it was a hard to spot dent in the magazine body.
My initial remedy was drilling out the dent, BUT, that opens up another issue, deburring, and smoothing the hole inside the magazine body.
That was too much hassle to my way of thinking, so I looked at the follower and found a drag mark in the spot of dent. So, I filed (see ground) a groove in the side of the follower body to clear the dents inside geometry.
After about a half hours work, The follower was able to traverse the length of the magazine body under its own weight with no binding. So, mission accomplished.
Next up is the corrosion on the outside of the magazine body, then refinishing it.