SAR-2 was my first AK back in 2003. I will always have a soft spot for it. <3
Anyway, about the only magazine I haven't had luck with is the Magpul AK-74 PMAG, the feed lips bump into the center support rivet and prevent it from rotating up all the way to lock. The md. 86-derived guns built on Romanian receivers (SAR-2, WASR-2, CUR-2, ROMAK-II, etc) have a center support rivet that is "out of spec" compared to the AK-74 design. (Note that this doesn't include kits built off AIMS-74 kits on US receivers, those use AK-74 pattern rivets.) Russia wouldn't share the AK-74 design with Romania as punishment due to them not toeing the good little international commie line. I surmise one could relieve the feed lips a bit where they bump but there are plenty of other options out there.
I've used:
- East German bakelites 30-rd mags
- Bulgarian Circle-10 red/brown/black 30-rd mags
- Bulgarian Circle-10 waffle RPK 45-rd mags
- Romanian md. 86 30-rd mags
- Russian bakelite RPK 45-rd mags
- Russian plum 30-rd mags
- Russian ribbed black 45-rd RPK-74M mags
- Polish WBP translucent 30-rd mags
Actually, as I'm listing everything, I'm reasonably certain the AC Unity 5.45 mags suffer the same issue as the Magpul mags. But there are obviously tons of options out there so two commercial mags not working with one specific type of AK-74 is small potatoes.
These are supposed to be pretty decent for a commercial magazine, but I don't know if they copy the Bulgarian pattern exactly at the feed lips so they fit with the SAR-2. I haven't tried them myself.