I've owned many AK's and lots of various mags., but I'm looking to stock up on some more "polymers".  I have a few Bulgarian waffles,( and they're great ),  but I have questions about the Bulgy flatsides on the market ( for about $15 ea. at CDNN specifically ).  I hear a lot of poo-pooing, and people classifying them as "range-mags" only.  I thought they were also steel fillet, lined.  What's the problem/difference ?  (I don't have one to examine).  Thanks.

i got 10 of them during the "panic" for ~$8-9 each. some of them were tight in both my aks but a little sanding fixed that issue. i havent had any problems with any of them since.

Good to hear !  I wonder if others share your positive impressions.

they work for me. i have lots of different ak mags and one of my aks doesnt like the cheap tapco ones but other than that they all function.

The 'Circle 10' mags I have work great, no issues. Then again I have yet to deliberately try and destroy them or my AK while using them... But going off the specs, how their made, etc, I think some people might just hate them because they are pricy. Which is the only negative for me anyway, otherwise I would be buying a bunch more right now

The ((10)) waffle mags are one of the best polymer magazines on the market.  The Bulgarian slabsides are commercial mags and lack steel reinforcement in key areas like the locking tab.  The feedlips might have a steel liner, but without reinforcement in critical locations they are just slightly better than Tapco mags at best.  I have 3 of these magazines, which function fine, but are relegated to range duty only due to their known shortcomings.