re: Is there a need for barrel break-in?

Depends on who made the barrel. High-end custom barrels are going to be polished out before they leave the factory, there's pretty much nothing to break-in at that point. Mass production CHF barrels don't need it either, the carbide mandrel the barrel was forged around will leave a polished surface finish inside the bore and no tooling marks. I experimented with my Ruger American, shooting 50 rounds through it and keeping track of the groups in 10 shot strings. Then I used a strong copper remover and cleaned the bore until no residue would show on the patch. Made absolutely no difference in how the rifle grouped when I shot it again. The CHF barrel doesn't care. Mass produced cut rifled barrels might be a different story due to tooling marks but from what I've read, even Remington 700s with awful tooling marks in the bores still produced good groups and didn't get any better with bore paste and a break-in regimen.