Just to clarify a few points:
1. Except for the 100-200 Hk 416 D rifles that were imported in semi auto, the 416 is not legal to own.
2. Some of the 416 D's were ordered in factory semi auto by LEA's because their personnel were fairly unsophisticated with machine guns and they didn't want to have them shooting full auto.
3. Someone realized that the 100-200 semi auto Hk 416s were improperly classified as NFA items. They had them reclassified by ATF as SBRs and then later removed them from the NFA registry altogether.
4. Those 100-200 rifles are the ONLY legal legitimate Hk 416s that a civilian can own.
5. Hk 416 uppers are more readily available and, because they are not a "gun", can be owned by anyone (except the 10.4" upper, I believe, needs to be registered as an SBR if you put it on a lower).
6. The 10.4", 16.5" and 20" authentic Hk 416 uppers sell for between $3.5k - $8k depending on condition.
7. If you see an Hk 416 upper advertised for $2,200 it is probably just a MR556 converted to a 416 style upper. Read the fine print.
8. The 416 is one bad @ss rifle. You can sh!t on it all you want but there is a reason it is used by the greatest assault teams ever organized. They can have whatever they want and the fact that they chose the Hk 416 to carry out one of the most important missions in military history speaks volumes.