I have several of the “Colt 7.62x39” AR-15 Mags. They are only standard Colt AR-15/M16 20 round Mags that have had the butt plate stamped Colt 7.62x39 on them. Ergo the problem with the Colt AR-15’s chambered for the Russian 7.62x39 round.
You can take any of the standard AR-15/M16 20 round Mags and use it and have the same results without paying a high price for a useless factory Mag. At present there are several 10 round AR-15 Mags that will work for you. However, there looks like another delay with C Products scheduled release of their AR 7.62x39 Mags.
Now if you “just” have to have the “Colt Factory” AR-15 Mag in 7.62x39, then I’ll see how many that I have and I’ll let you have them for just $87.00 each plus S&H. I then will be able to get 3 C Products AR 7.62x39 for my AR.
ArticWolf