Wont cycle eject, - Radical Firearms 16 in. 12.7x42 (.936) Upper Assembly

I checked everything new lower 335 Grain AA AMMO and the lower shot everything else except that Beowulf. I emailed Radical I called and no reply or response. I don’t think I’ll be buying anything of there’s again or will I recommend anything especially for their customer service, get the original Alexander Arms upper and save!