Long story short I bought a new Spikes Gen 2 Billet AR-15 upper and a Noveske NSR 15 Keymod Rail and Troy Claymore. The smith at the shop who builds some quality stuff only tourqed the nut to about 30-35 lbs. I advise him Noveske says 60-80 as per that pesky little thing called the instructions. I get told it will hold at this torque value. They were extremely busy and I am not an armorer. The last time I free floated a barrel on one of these I over indexed the barrel nut and my sights went all the way right and would not co-witness thus requiring me to buy a new upper and let someone else who knew what they were doing take care of install. It was not that much of a loss, it was a Stag Arms and my very first AR to mess around with, and that was a number of years ago.
So I am trying to zero in this new upper and rail with the same lower, same Troy flips, Aimpoint and Daniel Defense barrel and it starts out at the far left and it appears as though my rear sight is going to bottom out in order to zero. The groups go from left to right and back again I am chasing the zero around. I am at an indoor range benched and resting on a sandbag. On the last string the group opens up to the size of a tennis ball, I clear the rifle and hand it to a friend to shoot and the rail twists, so loose barrel nut. I take it to another smith as I am in that part of town and you can unthread the barrel nut by hand. He follows the instructions and we end up at right about 80 lbs of tourqe for things to line up. I have plans with my wife and am unable to go back to the range until this coming weekend.
I have googled foo'd but been unable to locate if a loose or under tourqed barrel nut can casue the rear sight to allmost bottom out and or groups to jump around like that with having play in the barrel? Thankfully the other smith looked over the upper and barrel and even miked it out an all is well. Thanks in adavnce
So I am trying to zero in this new upper and rail with the same lower, same Troy flips, Aimpoint and Daniel Defense barrel and it starts out at the far left and it appears as though my rear sight is going to bottom out in order to zero. The groups go from left to right and back again I am chasing the zero around. I am at an indoor range benched and resting on a sandbag. On the last string the group opens up to the size of a tennis ball, I clear the rifle and hand it to a friend to shoot and the rail twists, so loose barrel nut. I take it to another smith as I am in that part of town and you can unthread the barrel nut by hand. He follows the instructions and we end up at right about 80 lbs of tourqe for things to line up. I have plans with my wife and am unable to go back to the range until this coming weekend.
I have googled foo'd but been unable to locate if a loose or under tourqed barrel nut can casue the rear sight to allmost bottom out and or groups to jump around like that with having play in the barrel? Thankfully the other smith looked over the upper and barrel and even miked it out an all is well. Thanks in adavnce