FWIW....I used a Maclennan barrel in my 6mmBR build recently. I say recently because it finally got finished in February, but I waited 10 months to get it. I am pleased with the accuracy in this new rifle so I suppose a good thing came to me who waited. Rob did all the work to the prior barreled action.
His barrels don't fowl up much. The lapping was excellent. The cost of the barrel and install, trueing and cuting, crowning and threading was $700. He specifically made mine with a 1:13 twist which he had to cut himself. Perhaps this added to the wait time, but 10 months is a bit long.