Have 3 KAK barrels now, all mid-length 16" that were around $100 each. One is my trashcan gun that only shoots Steelcase wolf ammo and made from spare parts, and the others get mostly brass. I took the trash can gun out to 100 yards prone, and shot roughly 3 to 4 MOA, unscientifically measured. That one is not getting cleaned very often and gets mobile 1 as lube.
I have not performed the same test on the others, but they get brass and get cleaned. All three are Green Mountain blanks and Nitride treated.
For what I do, which is mostly plinking at steel and paper in fairly high volume, they seem as accurate as my Colt and LMT, again, without scientific backing.
For my purposes, the trashcan gun is a test, unscientifically, to see if I really notice a difference between it and a colt, LMT or FN barrel. This would be in accuracy as well as wearing out the barrel. I currently own an LMT 10.5 inch barrel that has close to 10,000 rounds through it with minimal loss of accuracy, so tough competition. It Will take me a while to finish the test
So far, so good.