I'm not an expert or marksman but my rifles outshoot me handily and my idea of barrel break-in is shoot till you're done (1 or 100+, makes no difference the round count unless it's dirty enough that it malfunctions or is no longer accurate, which has never happened to me), then clean it properly. I may be doing it all wrong but so far, so good.
I imagine most have read it before but I tend to follow Gale McMillan's take on barrel break-in, but I'm sure there may be exceptions to almost everything. I'd go with what the manufacturer recommends or what works for you.
How to Break-in a Barrel within AccurateShooter.com