Having worked with 1000 yard rifles for many years, I have found that if you are starting with a new stainless barrel, yes break it in a little. Shoot 5 or 10 rounds, scrub with a nylon brush, scrub with JB Bore paste, wash it out with disc brake cleaner, and fire again. The PCC barrels I have encountered are not lapped especially well inside. They can do with a little polishing to smooth out the lands at the end of the freebore.
If you are shooting a new chrome lined barrel (not chrome moly) then you don't need to break it in.
I am lucky in that I have a Hawkeye bore scope so I can view the interior of the barrel. Don't ever buy a Hawkeye because your rifle will never be clean again!
Eric