I believe that the benefits of breaking-in a barrel are pretty hard to quantify, but the consensus seems to be that breaking-in will make the barrel easier to clean, less fouling to contend with. Breaking-in might be a form of burnishing away tooling marks that might cause fouling. I believe that the idea is to remove carbon fouling between initial shots so that the carbon is not embedded or abrasive as successive shots are fired.
I know fellows who refuse to go through the break-in game and their barrels seem to shoot as well as anyones. Some barrel makers dispute the wisdom and others suggest breaking-in.
cleaning rod, jag and new bronze brushes
lots of appropriate sized patches
bolt lug lube, recess cleaning tool/swabs
Pressurized liquid cleaner - eg.
Shooter's Choice Quick Scrub for cleaning
One popular break-in procedure is as follows:
..run a dry patch down the bore and then fire one shot. Install a bore guide and use a good cleaning rod.
..run three or four carbon solvent soaked patches through the bore, discarding each one as it reaches the end of the bore.
..continue until the patch shows minimal discoloration
..put a few drops of carbon solvent on a new bronze brush and run it completely through the bore
..put two or three more drops of solvent on the brush as it extends through the muzzle and pull it back completely out of the chamber. Then go ten complete passes through the bore.
..run several carbon solvent soaked patches through the bore until virtually no discoloration
(at this point you could then run a copper solvent soaked patch down the bore, let sit for 5-10 minutes and check to see if there is any copper being removed by the presence of a blue-green color on another carbon solvent soaked patch).
..dry the bore with a clean patch and fire another shot.
**always wipe clean your cleaning rod each time you switch solvent types or after brushing
***always clean your bronze brushes after each use with a pressurized liquid cleaner such as Quick Scrub. No sense trying to CLEAN a bore with dirty brushes.
..repeat the cleaning regime, including checking and removing copper if it starts to accumulate
..fire ten shots with the above shoot-clean process (10 single shots so far)
..then switch to two shots and shoot-clean for five pairs (ten more shots)
..then fire two or three five shot groups with shoot-clean process between each group
(total of thirty or thirty five shots).
During the shooting you should ensure that your bolt lugs, recesses and bolt face are clean. Lube the lugs very lightly and put a dab of lube on the contact point at the base of your bolt handle where the camming takes place. Also wipe excess solvent and fouling from the muzzle each time you clean.
There are no doubt other breaking-in procedures, some simpler and some much more involved. We have used this one for many years and our barrels are remarkably easy to maintain - and they shoot well.
Good luck with your shooting.
Depends on custom barrel or factory. Several mftrs of custom barrels do recommend even going through a break in. Factory on other hand it is required. My latest spencer barrel never fouled from beginning and I quit breaking it in after 5 shots. Cleans up lot faster than any barrel I have seen and much faster than light gun Hart, but even that is not like a factory barrel and is relativel quick. Preceding post was good procedure for factory at least. Ask the mftr and see what they recommend if custom barrel.
One item of interest for guys not used to this. Many 1000 yard shooters have stopped using bronze brushes all together. They use nylon brushes. Reason is hard bristle nylon (I use Kleen Bore nylon brushes) do not leave any minute marks,(some guys think bronze do) and more importantly if you use bronze and use an copper cleaning solvent you will find your brush breaks down as you clean and you are still getting green color from the barrel. It is not from copper, rather it is coming from the brush. A bronze brush will normally only last 2 matches max before it has to be replaced. If custom barrel you will find a hard bristle nylon works just as well and does not break down giving you false green color. Try Barnes CR-10, Montezuma Extreme and then finish coating bore with some type of oil such as Kroil and then 2 dry patches.
As has been stated, breaking a barrel in is becoming a controversial subject. Some fellows swear by it and others bypass it entirely. Speedy Gonzales, the well known gunsmith and BR competitor, stated in a recent article that he doesn't believe in it at all and feels it only wears the barrel out faster. This is coming from a guy who shoots VERY small groups. Personally, I like to clean after the first 5 shots and then shoot as normal. Someday there may be a difinitive answer to this argument but don't hold your breath.