I've always shot in new barrels on my bolt guns. I have a new Uberti 1873 in .357 on the way. It will primarily be used banging steel inside of 50 yards with cast pills, but will occasionally see the rifle range. Is it worth shooting it in?
I handload and I like to fire form my brass before doing load development. I use the first 50 or 100 rounds through the barrel to do that, and to also test brass pressure signs within the published max/min load limits.
After this, a thorough cleaning, and I'm essentially done with barrel prep. I don't do it to deliberately break in a barrel; but that happens anyway, as it would if I did nothing but shoot and clean as I would later on in the barrel's lifespan.