Recently received after a fairly long wait a barrel that I thought might be a winner.  Hand lapped and all that good stuff.  Feels awesome when pushing a patch down the bore.  Broke it in according to the manufactures specification.  Very pleased that the displacement between suppressed (AAC SR-5) and not, a bare 1 inch vertical.  Only problem is that I can't seem to find a node that repeats. Mainly using IMR 8208 XBR and 77 grain match bullets.

So anyone running this sort of configuration and have any suggestions?

Rifle is a Colt lower, Mega upper, Midwest Ind. free float, JP adjustable gas block, Nightforce SHV 4 X 14, Giessle HiSpeed match trigger, FWIW

I have a Lothar Walthar barrel that when installed wouldn't group a pet load that has proven in multiple other AR's.
Very disappointing, developed a different load with a heavier bullet that did shoot great.
Took it on a prairie dog trip, shot about 1000 rds and had a blast.
Sighting in the following yr, used my original load just to see how it grouped, it now performed as my other AR's, slightly tighter groups, very happy now!
Moral of the story, keep shooting, some barrels take longer to "break in".

I would remove the can first to eliminate that as a cause.

I can never get bipods to shoot as well as using bags front and rear for groups.

I need round black targets, not orange targets and not squiggly magic marker dots. It makes a difference how well I center the crosshairs.

Clean your barrel really well, especially when new.

If you have a chronograph I would use it when testing loads. 77 grain bullets usually shoot best for me between 2550 fps up to 2650 fps from my 20" barrels. I consider 2650 fps maximum from a 20". Subtract 50 fps for an 18" barrel.

Pretty much what I am seeing.  Back from the range today finally with a smile on my face.  Also your comment about a load that shot in other rifles now shooting, in this case is exactly on the money.  Round count logged is now 453 rounds.

Thank you for your response.

No doubt the suppressor might affect harmonics, but that is how I shoot these "deaf as a doornail days."  I will not say that could be an issue, but I have shot both with and without thinking it might be an issue and found it was not.  I also shoot from sand bags, as there is a greater steadiness.  As to target style, I find for my eyes I can locate or center the reticle better with a contrasting color, such as orange, than if I was trying to hold black on black.  I run a LabRadar unit and have seen many single digit SD's with very low extreme spreads which did not shoot consistently.  However, as the post above (my response) mentions that is changing and simply put this barrel is a slow learner. :-)

My favorite load of IMR 8208 XBR and the 77 Berger OTM while above your suggested velocity range, gave a .656" 5shot today with the best 4 of those going .362"

I truly appreciate your response, thank you

Two first things I would try is remove the can and try some 69 SMK. They tend to be more fault tolerant and you can always go back to 77s.