Originally Posted by HK35
But that doesn't answer the question about changing or adding a part to a personal firearm which is not covered under 922R.
Where in 922R or any other US law does it say that personal firearms are not covered? It boils down to you can only import shotguns that have 5 rounds or less capacity. The ATF defines that in order not to be imported, it must not have more than 10 parts made from imported parts. ATF defines what those parts are. So if you want to make your imported M4 have more than 5 round capacity, then you need to bring your parts down to 10. The M4 has 13 parts that are not made in the USA in the 5 round imported configuration. If you do not modify the M4 to more than 5 rounds, you are not required to change anything. The import issue is why the Versa Max has more than 5 rounds without any parts change issues since it's already USA made.