There are several sources still out there.
As far as working, any Eastern European steel magazine qualifies as a good one.
Both of these places are good, I have used them often.
Avoid any magazine made in America.
If you want polymer, use only Bulgarian, nice but pricey. The ones below are all steel.
http://www.aimsurplus.com/
http://www.copesdistributing.net/
From AIM: http://www.aimsurplus.com/acatalog/Surplus_Steel_30rd_7.62x39_Magazine_for_AK_type_Rifles.html
From Copes:
http://www.copesdistributing.net/product_info.php?cPath=32_34&products_id=1168
http://www.copesdistributing.net/product_info.php?cPath=32_34&products_id=1208
These are Hungarian 20 round mags, nice quality:
http://www.copesdistributing.net/product_info.php?cPath=32_34&products_id=268
As far as working, any Eastern European steel magazine qualifies as a good one.
Both of these places are good, I have used them often.
Avoid any magazine made in America.
If you want polymer, use only Bulgarian, nice but pricey. The ones below are all steel.
http://www.aimsurplus.com/
http://www.copesdistributing.net/
From AIM: http://www.aimsurplus.com/acatalog/Surplus_Steel_30rd_7.62x39_Magazine_for_AK_type_Rifles.html
From Copes:
http://www.copesdistributing.net/product_info.php?cPath=32_34&products_id=1168
http://www.copesdistributing.net/product_info.php?cPath=32_34&products_id=1208
These are Hungarian 20 round mags, nice quality:
http://www.copesdistributing.net/product_info.php?cPath=32_34&products_id=268