December 7, 2008
I have an H&K 416 with an extensive spare parts kit that I purchased from Center of Mass Firearms and H&K Parts.Net.
In my very careful side by side examination of the H&K 416 and the standard AR bolt parts, the only parts I see that are – and I have successfully interchanged are the: Ejector, Ejector Spring, Ejector Pin, Extractor Spring (with insert) and Cam Pin.
Because of the oblivious H&K bolt proprietary design, the Extractor, Extractor Spring, and the Extractor retaining pin cannot be interchanged with the standard AR parts.
Hope this helps!