I had a similar issue (not with DD) so I know how you feel. Nothing sucks more than getting that new gun to the range and then not even be able to enjoy it. Good news is you found out at the range and not while someone was breaking into your house. For what its worth DD has the best customer service if any rifle company I've ever had to deal with. I had a simple cosmetic issue with my new ddm4a1, I emailed DD and within 20 minutes I got an email back, my issue was forwarded to warranty and within 24 hours I got a shipping label to return the rifle. I boxed it up and returned it and 5 days later it was on it's way back. Exactly 1 week after first sending my email I had my rifle back in my hands and it was perfect. I would just email them tomorrow and explain the problem. You may be able to strip the rifle down and repair it yourself no problem, but then again you may find that the gas block, the gas tube, the gas port in the barrel, the cut in barrel for the taper pin, or something else may be put of spec... and then your gonna have to send it back anyway. If DD strips it down and finds something is out of spec then parts are going to get replaced then and there. I know it sucks, but I would just let them handle it knowing that it will be back in your hands asap. For what a DD costs I would wait an extra week to have it be perfect. Hope it works out for ya.