What is the proper break-in for a rifle barrel?
There seems to be an obsession with the subjects of barrel break-in on the Internet. Don’t worry about it. Just sight the rifle in and clean normally after you get home. Most shooters probably go through 20 to 40 rounds per range session, which is just fine. Whenever shooting any rifle, of any age, avoid heating the barrel unnecessarily. Heat speeds erosion. That is why I prefer to shoot 3-shot groups (instead of 5 or 10 shot groups) at the range, and why I let the barrel cool after every group with standard caliber and after every shot in the case of ultra-high velocity calibers like the .220 Swift or .257 Weatherby. High velocity and burning large amounts of powder per shot create a lot of heat and accelerate erosion, so shoot moderate loads and moderate calibers if you are concerned about barrel life. This is good advice whether the barrel is new or old.
