Hi guys,
I'm by no means an expert, but it seems to me that standard barrells need shooting in and good quality, custom barrells (ie. Pac-Nor) need less running in because they have a better finish inside. Hence, some quality barrell makers don't recommend a breakin for thier barrells. Tubbs offers lapping bullets and Savage has a guide on thier site on how to break in thier barrells. These guys know what they are talking about.
Talk of barrell makers making up the story that barrells need to be brocken in so as to sell more barrells is along side other great myths like Santa Clause. Keep believing if it makes you happy.
The short of it is if you have a standard off teh shelf rifle you probablywouldbe wise to shoot "n" clean it in. If you have a Lilja or Pac-Nor barrell do what they say, but I wouldn't be surprised if it didn't need shoot "n" clean.
Thanks and have fun