The receivers are also designed so that you cannot install an AK pistol grip.
I believe all this was designed into the rifle so that there would be no problems in importing it while the AW ban was in effect.
Jed you are probably right...about it not taking AK mags...I have seen conversions on them
Krebs does a real nice one...and they will take AK mags and PGrips Folding Stocks etc..