Note at all.
There are in reality 4 styles of 762 AR:
1) Original AR10 -- no longer in production
2) In 1989 C. Reed Knight Jr. and Eugene (Gene) Morrison Stoner started building the SR-25 (Stoner Rifle, and AR-15 and AR-10 = 25).
This used many M16 parts as possible to cut down costs (and subsequently many where replaced with purpose built parts as a 5.56mm part in many areas does not suffice).
The SR-25 is the basis for many of the other 7.62 AR style guns -- they use the original AR-10 magazine design.
3) Eagle Arms (who bought the rights to Armalite) started making a gun based off the M-14 magazine.
4) Now Hk started making the Hk417/MR308 -- while a piston gun, and a unique mag, they use the 'full size' bolt carrier idea of the original AR-10, the SR-25 and current AR-10 guns use the M16 diameter buffer tubes - and the full size bolt carrier is a no go on that.
are any parts for the HK interchangeable with the real AR-10s then? bolts, buffer tubes, stocks?