I'm very happy to hear you have stopped selling these rifles.
I don't recall the conversation with the owner of the rifle, nor his responses as to re-contacting you concerning the rifle. Regardless, I am confident I recommended this course of action as the barrel gas port dimension is essentially cannot be repaired. The only solution would be to replace the barrel. Nevertheless, many gun purchasers who received new non-functional firearms are HIGHLY hesitant to return to the original seller, and simply want to invest in getting the firearm fixed.
Thank you for you response to the review.