Radical firearms 16in. 5.56 socom upper assembly - many failures - Radical Firearms 16 in. 5.56 SOCOM Upper Assembly

Would be a great setup if it would actually work. I have experienced constant issues with this upper. It has had problems jamming, complete failures to feed rounds, and the bolt will sometimes fail to lock back after the last round fired. I have sent the upper back to the manufacturer Radical Firearms (which costs additional money), and they say they cannot find any issues and sent it back. Upon receiving the upper back, it continues to have the exact same issues. Optics Planet will not return the item and I am proceeding with Optics Planet product support in hopes that something can be resolved. At this point, I have purchased a completely useless upper.