Finally....

[Schuetzenman]

Interesting. So do I just measure the the circumference of the magazines just above the latch lug? Is there more variation in the mags themselves than rifle mag wells? So then theoretically the magazines that did fit properly have a smaller circumference?

All magazines are a rectangle and at the corners they are not dead square but rounded. The Wasr mag wells being milled out often have a radius in the corner of the mag well that are smaller than the radius in the corner of the magazine. As you try to rock it into position it binds up at the corners usually. It is rare that the straight sided openings of the mag well scrape on the mag body, usually only at the corners. With a Polymer mag you can force it a little to see where it is rubbing and then focus on metal removal at the corner of the mag well opening.

[imanaknut]

Just to add gas to the fire, I had an SAR-1 that when I locked in the first mag, the rifle refused to let go of it. It took some aeronautical ingenuity to get enough leverage on the locking lever to move it without bending it. Turned out the second mag did the same thing. A check of the locking lever showed a nice burr on it. Not something usual on any AK, but it did require taking a file to the rifle to get it to release a mag. It was funny that it would allow the mag in, but not release it.

I was lucky with any problem mags because if I had a problem with one mag and rifle, I had enough AK variants to check to see if it was a mag issue or rifle.

As for the mag well opening, I have heard of people having the issue that Schuetzenman described. I have seen Century opened mag wells from what looked like they were opened with a can opener, to one that looked factory. They were not known for taking care when using enough parts to make the imported rifle compliant with the sporting purpose clause of the new ATF second amendment, or care when opening the mag well to use standard AK mags.

Sad as there are a lot of firearms in this country that if it weren't for Century, we would never have them here in the land of shall not be infringed.