I changed out every part i think I could, trigger, bolt, FP BCG spring, weights. The thing that really pisses me off is that every once in while something works and then you can not repeat it. If it would just stay one thing, I could work on it. AArrrgghhhh!!!
I think you are correctNice build. It does look like your hammer spring is in correctly, so that's out. The marring from the cam pin should tell you something is out of spec, or incompatible causing the issue you are experiencing. Getting the head space gauges is good idea, but won't do you and good until you figure out why the receiver is getting chewed up. Need to consider the BCG, receiver and barrel extension.