Congratulations on the new Cooper! I used to go into a shop in Boise quite a bit that stocked Coopers. They sure are fine rifles!
Barre break-in is a thing that has come about because people want it. It was 'invented' by a competitor of Gale McMillan's (that according to McMillan in a years-old public posting) to sell more barrels, since every round down a barrel uses up a percentage of its useful life. However, it has persisted because a significant number of people _want_ there to be a break-in procedure. They want to have a procedure, so the salesmen sell them what they want. Is there any harm in that? Whether you _want_ there to be benefit or harm will be far and away the largest determinant of whether there's any harm in it, or any help.
My break-in routine is: Go shoot. When I'm done, I clean the barrel and see how it is. If I shot, say, 20 or 30 rounds and clean-up takes 2 hours, I'll be disappointed. Maybe I'll scrub it with bore paste or something like that, or maybe I'll just shoot it a little more at a little higher rate of fire next time. Or maybe not.
