Maybe I'm missing something since I am a bit of a newbie on all this, but...
I believe if you add a 30 round mag to a Saiga sport rifle, it becomes an illegal assault rifle UNLESS the rifle is made 922r compliant. In other words what you are proposing to do makes the gun illegal. I think this is what hutchsaiga was trying to tell you.
However, to make the rifle 922r compliant, you need to replace a number of the foreign made parts with US made parts. Thus, you will end up "converting" it anyway...unless you want to be running around with an illegal piece.
I have an AK-47 already
