Each manufacturer has their own instructions/recommendations. I have always tried to follow the specific manufacturer's recommendations. There are also differences in recommendations between barrel materials/finishes so make sure you are following the correct procedure for the actual model you have.
Here is Weatherby's recommendation -
https://weatherby.com/faqs/what-does-weatherby-recommend-as-a-break-in-procedure/
Here is Remington's -
To properly break in or "season" a rifle barrel we recommend you use a good quality cleaning rod, a good quality bronze brush and patch tip, flannel patches and quality bore solvent. (we recommend the use of Remington Brite Bore Cleaner & Rem Oil).
INSTRUCTIONS:
For the first 20 shots, you should do the following:
For the first (10) shots:
Run a patch saturated with Rem Oil through the bore after each of the first 10 shots, and follow up with a patch saturated with Remington Brite Bore, and finally a clean patch to remove all residue.
For each of the next 10 shots, run a patch saturated with Rem Oil through the bore after every two shots, and follow up with a patch saturated with Remington Brite Bore, and finally a clean patch to remove all residue. Now follow the cleaning guidelines below:
To ensure the highest possible barrel quality/life, you should repeat this cleaning procedure every 20-25 shots until the barrel has had at least 100 rounds through it. Failure to do so could result in excessive build up of fouling (copper/lead deposits) in the bore causing decreased accuracy and requiring more frequent cleaning between shots.
Other manufacturers do not have a recommendation, like Ruger.
Hope this helps!
