I started breaking in new factory barrels years ago and completely believe that it has helped. They are rougher and seem to smoothe out better when this is done. I just bought a Broughton that will be installed soon and I'm thinking that I will play it by ear and see what the barrel tells me, but I doubt it will require near the same break in period as the others.
I've been getting away from using brushes for the most part. I've had great luck with wipe out followed by some hoppes to get the crud out. I've noticed that when I brush, it takes a long time to get them to settle down again. Even just using hoppes a few days gets them real clean. Typically I soak and jag to get most of the loose carbon out, then soak them muzzle down on a clean white sock several times followed by a jag and fresh patch. This works real well but does take longer.
This is part of an article I wrote for Len, should appear next month but since it was brought up, I think this portion applies to the topic. Reference custom barrels.
Barrel brake in;
This could be the most debated subject of barrel care. The two schools of thought are, just shoot it, or shoot and clean for x# of rounds. I have tried both and from my experience the proper way to go is the shoot and clean, this is why.
It is a well known fact that a barrel, even a custom lapped barrel will attract more copper fouling to the bore on the first few bullets down the tube. The single most important reason to shoot one and clean out that copper fouling, is to prevent a build-up which will be MORE difficult to remove if multiple bullets are fired down the virgin bore. Yes we may clean it five times with 5 bullets fired, but you will notice that the fifth cleaning was much easier than the first. On the other hand if we fire 5 bullets in succession we will have multiple layers of copper laid down, which will require more cleaning to remove. My opinion is that the 5 cleanings will leave your bore in better condition than the single cleaning after 5 shots. I have shot, bore scoped, and cleaned a couple of barrels during the brake in, and the visual bore inspection was quite enlightening. So what is happening as these first few bullets pass down the clean barrel? Good question answers range from; burnishing the surface of the barrel, smoothing out the throat, to depositing carbon in the grooves of the micro finish. I cannot say for certain, but the results of a broken in barrel do have a noticeable effect. Now all this is not to say a barrel that had 20 rounds fired down it right from the start will not brake in. I feel the barrel will get there quicker with fewer rounds and less scrubbing, cared for the way I have outlined.
Now not all barrels will act the same, the surface finish, steel type, hardness, cartridge, and lubricity, can all affect the barrels ability to ďbrake-inĒ so none of this is set in stone. You may find that your barrel cleans up easily after 3 shoot and cleans, another barrel may take 12 shoot and cleans.
One other overlooked aspect is the period of time in which the barrel stabilizes. Now donít read more into this than what Iím saying. But if you load 75 cartridges exactly the same and fire them through a new bore. At the same time you did a few shoot and clean, and the barrel is cleaning up easily. You will notice that the velocity readings of these 75 bullets may be a little erratic, and will most likely increase through this period of use. After the 60th or so bullet the velocity readings should equalize and may be up to 50 fps faster than the first 20-40 bullets. This was not my finding, but pointed out to me by a friend who has broke in many more barrels than I, since that time I have seen it enough to believe it.
My procedure is exactly this; Shoot one round, remove all copper, one dry patch, one wet patch of Kroil, one dry patch, repeat about 5 times total. Shoot 5 rounds, remove all copper, one dry patch, one wet patch of Kroil, one dry patch. At this point 95% of the barrels I use will be cleaning up extremely quick and easy, and I will begin some form of load development. I will usually try and get another 2 cleanings in the next 50 rounds or so, and monitor the progress with the bore scope. After this I consider cleaning to be routine and will follow the advice in the second paragraph bellow.
Many years ago I traded a very good friend for his European made mauser in 375 H&H. Beauty and Elogance were amazing. For years this gun was his elk and moose gun until one day it went from one inch groups to 5 inch groups.
Note: He never ever cleaned a gun. I got the gun because it was the only 7 pound 375 H&H I had ever seen. I was going to replace the barrel.
For the following week after I got the gun I alternated every day between copper solvent and bore cleaner. For twenty years of never cleaning the barrel there were layers upon layers of copper then burnt black carbon. Then I got down to the last layer of copper which was instead of layered was mixed with carbon. It would not clean period. I plugged the muzzle end of the barrel,stood the barreled action on the muzzle end and filled the barrel with WD 40 and left the gun standing in the corner this way for a week. After seven days I pulled the plug and went to work starting with nylon brush and then going to brass brush. Guess I thought I was going to restore the barrel. The carbon was gone leaving long coper colored sheens in the bore. Copper solvent wasn't getting it done so straight ammonia was used for a ten minute soak. ( That blue on your patch after using copper remover is the amonia chemical reaction with copper) Caution: Ammonia etches steel!!!
I got all of everything out of the barrel and inspected very closely the bare metal. Whomever made the barrel did not understand the principle of lapping a bore. It looked like a pitted gravel road of tool marks. In my opinion this barrel should never have been put on a gun but its an example of shooting and depositing material. Over the years of filling and smoothing, it got to the point the barrels bore became undersized to the point that he had to drop his powder charge because of loose primers from over pressure.
The auto industry breakin period says it best. Don't run your new vehicles over a certain speed which interprets to RPM's for a period of time. Change oil according to instructions to get out the shaved material during this seating period then one is good to go.
After cleaning it, you could have fixed your friends 375H&H through firelapping.
Automotive engine break-in amounts to tailor fitting imperfect parts TOGETHER, through rational controlled wear. Round piston rings to an oblong bore. With a little wear from both you get a perfect fit and extended life. Too much wear and life is greatly reduced as the rings will continue to turn. Same with lifters to the cam, and pretty much every other mating parts that aren't matched. With better parts, perfectly matched, you don't have to break-in, and still get the full minute of top-fuel dragster engine life!
But barrels don't wear from passing copper jacketed bullets, and every bullet goes down the bore a bit differently. So there is no correlation here with engine break-in. Breaking-in a barrel will not make it last longer, nor shorten it's life, as with an engine. It won't make the barrel shoot better either.
Lets just accept that barrel break-in doesn't happen at all.
Lapping is another matter. Barrels should be lapped, not just to smooth over machining(reducing copper fouling), but to ensure proper final dimensions needed for accuracy.
Unfortuantely, barrel makers have yet to determine and set dimensions(through lapping) to any standard. They do not even measure the bores they sell.
This is a huge contributor to the unpredictability in barrel performance that we have come to accept. It's why no brand is better than another..
Anyway, my lapping, or smoothing out the throating jaggies, amounts to 10 Tubbs firelapping rounds. I dress up the lands a bit every few hundred rounds with another.
I would like to make another comment about barrel break in ,Tim north told me to shoot one round clean then push a small drop of oil on a patch down the barrel shoot again and repeat do this for 20 or so rounds until the barrel stoped fauling and had little to no coper signs then start shooting some 3 shot groups and repeat the above method for cleaning he told me that the barrel would start to settle down and my MV would reach it's maximum at or around 80 to 100 rounds he was exactly right as my chrony varified everything he had told me. Just wanted to share that with you fellas.
"Molon Labe" IN DIXIE WE DON"T CALL 911 !