This has come up fairly often, and there seems to be an even split of opinions as to whether or not it serves any purpose. I believe it does but many say no - just shoot.
For what is it worth my procedure is as follows-
-Soak the inside of the barrel with a good brand of solvent
-Brush out the barrel with a tight fitting bore brush
-patch out with one wet followed by two dry patches - repeat if required
-apply one patch soaked in Kroil
-fire one round
-soak bore with Sweets
-wait 10 minutes then patch out
-repeat for a total of 5 rounds applying Kroil between shots and cleaning with Sweets
-begin shooting 3 shot groups applying Kroil between groups and cleaning with Sweets as above
-repeat for 15 rounds
-begin shooting 5 shot groups then applying Kroil and cleaning with Sweets as above
-after 50 rounds fouling should of deminished, if not continue with cleaning every 5 rounds.
Go to
www.Kriegerbarrels.com then check out the link for barrel break in and cleaning from the right hand side of the page. This explains what is being accomplished by the break in proceedure, although the technique differs from mine.