And the stock, no matter how many US parts it comes in, counts as 1 PART.
The magazine counts as 2 PARTS.
A lot of the other add -on stuff, like scope mounts, bipods, etc, DOES NOT COUNT AT ALL.
Go to the list in the stickies section of Legal Issues here and look at the 14 part list.
Those are the ONLY parts that count, and they only count as 1 part each.