It pays to pay attention,

[1Shot]

I did my second complete AR build today. I used an Anderson upper, Toolcraft BCG, Oden Works 18" 223 W barrel with the their tunable gas block and I used Blue thread locker to bed. I used a STNGR Hawk 15" float tube. When I put the tube on I noticed that the gas block was touching the tube on the inside on one side and you could barely see light on the other side. Out came the dremal and file and now there is plenty of wiggle room between them. This made me think, I did not even think to check this on my first full build which was my 6.5 Grendel. I used the same make barrel and gas block and float tube. Sure enough same situation. Now I have shot this and with certain loads it shot great. But I have seen all my life that with bolt rifles if the barrel is touching anything you usually do not get the full accuracy potential out of it. So I took the tube off and out came the dremal again. I was lucky that this is an intermediate length gas barrel and with my flex attachment wand I could just reach where I needed to grind. Now there is plenty of wiggle room on this one. Maybe it might shoot Hornady 123 SST bullets now which it would not before. Hope to get to the range this week sometime.

[BCHunter]

The Devil is always in the details.
I hope it helps with the 123 sst but I wouldn't be on it , from a lot of threads that seems to be one of the most difficult to get good groups with.

[Sticks]

I did my second complete AR build today. I used an Anderson upper, Toolcraft BCG, Oden Works 18" 223 W barrel with the their tunable gas block and I used Blue thread locker to bed. I used a STNGR Hawk 15" float tube. When I put the tube on I noticed that the gas block was touching the tube on the inside on one side and you could barely see light on the other side. Out came the dremal and file and now there is plenty of wiggle room between them. This made me think, I did not even think to check this on my first full build which was my 6.5 Grendel. I used the same make barrel and gas block and float tube. Sure enough same situation. Now I have shot this and with certain loads it shot great. But I have seen all my life that with bolt rifles if the barrel is touching anything you usually do not get the full accuracy potential out of it. So I took the tube off and out came the dremal again. I was lucky that this is an intermediate length gas barrel and with my flex attachment wand I could just reach where I needed to grind. Now there is plenty of wiggle room on this one. Maybe it might shoot Hornady 123 SST bullets now which it would not before. Hope to get to the range this week sometime.

I have a high end upper that arrived with the GB canted, but not close to touching. Was still getting contact from barrel whip on that side, and the bottom. Upper has since been stripped down (not at all happy about the locktite on the barrel nut), accurized, and reassembled.

Frame by frame viewing of shots fired showed severe barrel whip down. Odin Atlas muzzle brake. Might be handguard flex, but I preload the bipod pretty heavy.

Have not shot it since other than scope zeroing. Hope finding yours fixes it.