Tom: Greener seemed to think that "burnished" barrels improved patterns; 30,000 rounds with improved full choke pattern
https://books.google.com/books?id=inQCAAAAYAAJ&pg=PA227

I've not come across any study, vintage or modern, directly comparing pitted (and how to determine the level of pitting?) with smooth bores.
Of course a number of trap barrel specialist smiths, and their disciples, claim improved patterns with bore honing and choke magic wink

"Pattern Testing Results - Four Guns, One with a Wilkinson Barrel"
Neil Winston's comments start on p.6 and continue but unfortunately the images have been lost
https://www.trapshooters.com/thread...guns-one-with-a-wilkinson-barrel.302858/