Are we talking about a 7.62X39 Saiga? If so, the modification involved has nothing to do with the magwell itself--the factory latch is just about 1/16" or so too long. I've modified two rifles to accept standard magazines, and have encountered no problems relating to the magazine well. You will also need to install a feed ramp in the rifle, as the Saiga magazines have a higher front and cartridges tend to miss the chamber low when feeding from a standard AK mag. 922r is ridiculously complicated, but a cursory internet search should turn up the list of parts covered by the law, along with how many of them must be replaced with US made parts before the rifle can be "de-sporterized." There's been some suggestion that the addition of a standard 30rd mag may not per se make the rifle "non-sporting," but the subject is foggy enough that a full conversion would be advisable.