Like others I don't really follow a "break in" routine. I simply clean the rifle really good before the first range session and shoot it butnever let it get to hot - 3 shot groups max when weather allows. Then completely clean the bore and a do it all over again...and so on!!
If upon intial or follow up cleaning I think hand lapping will be a benefit I break out the JB Bore Paste and elbow grease.