Yeah, start over. Best advise, if you are somewhat new to the 308AR / AR10 world, is buy a gun and don't build it. The .308 rifle parts are all over the place in terms of lack of compatibility. The .308 gas gun is not like the AR16 / M4 / M16, where almost every part is interchangeable. Start with the premise that nothing fits together, and occasionally you find parts which do. Hell, even Armalite has a Type A and a Type B AR10. One is AR10 compatible and one is DPMS compatible. Go figure that one out.