I'm building my first AR-15 and am having a Failure to Extract issue. I found this thread on thehighroad.org with this description which seems to be an accurate description of what is happening: http://www.thehighroad.org/showthread.php?t=407909 It's a 14.5 Barrel (with pinned+welded flash hider) brand new BCG etc. Everything appears to be tight and it ejects when manually cycled. I'm thinking it's the Buffer. I'm just using whatever came with the CAA CBST stock - but can't tell what weight of buffer it is. I don't think I have a scale that can weigh it accurately. Any other suggestions? Should I go with the H2 Buffer and see where that gets me? Should I go straight to the H3 Buffer? Any advice appreciated. PB What do you more experienced builders recommend? The H2 or the H3 Buffer.