Well, here's my 2-cents ...
About 5 yrs ago I had a local 'smith put together a WOA SPR upper, using their receiver, WOA 18" SS barrel and 12" DD rail. I also had him install a Geissle DMR trigger, the adjustable one, in a RRA lower and set it up for a very light pull ...
Problem was, it never shot better than 1.5-2.0 MOA @ 100yds from a bipod and rear bag rest. I've been shooting for 40-some years, have shot in the Nat'l Matches and local Hi-power comps, so I was pretty certain I wasn't the problem, or even a contributing factor ...
I tried various factory match ammo, my handloads, different bullet-weights, yadda yadda.
Once in a while I'd group 5 shots just a tad under 1 MOA @ 100yds, but that was rare.
Over time I'd been re-thinking the DD rail which proved, for my needs anyway, to be too heavy. So about a year ago I bought a PRI Gen III rifle-length tube (the one w/ the top rail and short rails @ 3, 6, & 9 o'clock) and had a different 'smith do the install. After explaining the accuracy issues I was having with match-grade ammo, I asked him to recheck all the torque specs, etc., as well as the trigger and make adjustments as needed.
Well, he found the trigger to be fine, but broke a wrench just getting the barrel nut off. He found several things out-of-spec, including the torque.
But once he installed the PRI tube and had it properly torqued, not only was it a lighter set up over all, but on my first outing w/ Norma's 77 .223 match ammo, the rifle shot one ragged hole @ 100yds - maybe a .75"
Long story short, it wasn't a barrel problem. It was an install problem, courtesy of the first 'smith.
I don't have the know-how or tools to do it myself, but having a competent AR 'smith set it up right the first time prevents these sorts of aggravations and extra expenses down the road.
I'm quite happy w/ the way my WOA SPR shoots now, although I haven't been able to reload much for her due to lack of time and job distractions.
Again, just my experience.