Not trying (consciously) to sound stupid. Just trying to figure out if "brand" ... like the difference between those two barrels ... will have a greater difference than the combination of multiple other entering arguments.
This is just my opinion for what that's worth. There's many reasons why you should pay more for a premium barrel vs. bullet hose quality.
If it's a button rifled barrel, how many previous barrels were cut using the same button? How crisp is the rifling and is it of correct depth, bore vs. groove? is the twist rate consistent or what percentage can it vary to what is marked on the barrel?
Is it a company where barrel after barrel is banged out and QC is just a random sample at this point because X are sold and no complaints are received? Is Jimmy running the machinery hungover this morning and really doesn't give a crap if the steel sang a little differently while the tooling was run through it or profiling it? Was the barrel properly heat treated or stress relieved?
Is the company known as producing accurate barrels used by good shooters at distance or known for churning out 5.56 bullet squishers used at distances less than 100 yards?
Is the barrel actually lapped or air gauged when finished? Ultimately you're paying more for the time and quality control the manufacturer can put into it. That and the fact that when it's assembled into an upper you have high confidence that it will actually shoot respectably. Hearing about cheap barrels that actually shoot on the internet is like hearing somebody won the lottery, one out of many.
It would be interesting to see what your 18" barrel would do with 60 grain bullets or even using Mexican Match Federal 75, pulling the TMJs and seating 77 TMKs in their place.
I would put at least 100 rounds through a WOA barrel before judging. If it still won't shoot, strip all the copper out of the barrel and start over using less aggressive cleaning. I hope you find a solution, this can be a frustrating journey.
