Ok I have basically same build. Bear creek ar10 in 22-250. Will cycle but will not pick up next round. Found bolt not coming all the way back to pick it up. Removed buffer it weighs 106 grains. Took it apart removed weights 1 at a time has 2. 1st weight dropped it down to 88 grains still does not cycle removed all weights. It now weighs 68 grains and it cycles fine now no issues. I'm also running 40gr vmax bullet at 4100fps. I checked this with other ar15. There buffers are around 88 grains but there are long and will not work in the ar10. Hope this helps...
