IThe breakin procedure suggested for my match AR barrel was:
Fire one - chean, repeat 3-5 times
Fire three - clean, repeat 3-5 times
Fire 5 - clean, repeat 3-5 times
Fire 10 - clean, repeat...
Until 70-100 shots - then all set.
It took me 2 long trips to the range (of course with all cleaning supplies). I don't know if it made any difference, but IMO it is worth it if that is what the barrel maker suggested.