Hera stock ! - HERA Arms CQR-AR10 Buttstock

I checked the reviews before l ordered this budd stock , it's looks good and l ordered 5 sets of it , 3 AR10 and 2 AR 15 , AR 15 and AR10 black color is back order and l cancelled both today , try to installed the AR 10 ODG it's doesn't fit at all , l even took it to the gun store down a block from my house , have the gun smith take a look at it , he said it won't work , told me to return it if l can ! I'm so disappointed may be this stock only work with HERA Arms , it's doesn't work with AERO PRECISION M5 !