Just got a customers AR built and system checks were all good, fired 3 rounds through it before I handed it off. He gets home and gets 4 rounds out the pipe and tells me it did not fire, but there was a live round in the chamber. Said he could push the trigger forward and then it would fire in that situation. I thought right away either I screwed up the spring installing or it was faulty. Told me at first there was no pin strike on the primer what so ever. Then the next day, he said he saw a slight strike on a round that failed to fire. I took the lower apart and ensured everything was good, function test was good, parts seemed to be good to go. He goes back home and has the same issue. So about every 3 - 4 rounds he is getting a fail to fire. I'm down to wondering if the bolt is not seating correctly, which I will be looking at today at the range, or something is wrong with the firing pin......
Anyone have any issues like this before? I have not seen anything like it in the 5 years I have been building these for people.
Thanks