Re: My new Stag Arms 5.56. (first time shooting it) ..problems
It is time to take that dealer to task for what he did to your gun and the delay in your enjoyment of same. The only way he'll know he screwed up is for you to show him that you are a little bit upset.
There are only so many things it could be but without the gun in hand to disassemble, as you did, there is not a surefire way to tell exactly what is wrong. The call to use commercial ammo was the least intrusive suggestion. If any of us had the gun in hand we may have started with the gas system after trying commercial ammo.
Don't feel cheated as all of us have had some unknowing or uncaring person mess up a gun or two. I had a Garand re-barreled years ago and I could not get it to cycle after the re-barrel. After much investigation and kind of by dumb luck and after changing out several parts, I found the barrel manufacturer had not drilled the gas port all the way through which minimize the gas getting to the operating rod piston.
Recently my son-in-law bought a CMP Garand (we have guns other than Garands!) and the hammer was following the bolt in recoil and not staying cocked after every shot. I took it home and investigated. The assembler at CMP had installed the hammer spring housing in the trigger group wrong side out. I let CMP know about it immediately and the president (or was it CEO ?) contacted me via email to assure me they would find out why that assembler wasn't paying attention or was unknowing. He thanked me for bringing it to his attention. You need to inform that dealer of his mistake so he won't do it again to someone else.