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Discussion Starter · #1 ·
I have heard a lot of conflicting answers to this, what does the YB crowd think.
My new RPR doesn't say squat about any kind of barrel break in.
My Savage .338 did not say anything either.
Noveske says they see no difference between doing it or not.
Krieger says it is a definite YES! must be broke in.
My gunsmith is not a big believer that it is a must.

Thoughts?
 

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A co-worker was a R&D Eng for one of the big firearm manufactures, and he does all his new barrels. Helps smooth all the imperfections in the barrel. I think it helps keep copper fouling more manageable. I do it to all mine. What harm will it do, just takes time, may help with barrel life.

Mark
 

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I stopped doing it when Tony Boyer said it was a waste of time....
 

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I didn’t break in the AR, but I did break in my Rem 700 & my RPR per my gunsmith’s recommendation. Can’t hurt & you get to spend the day outdoors. Bring a second rifle so you don’t get bored. Took about 100+ rounds before it grouped well.
Nosler says break it in.
I also think there’s a bigger need with a production barrel vs a high end custom barrel that’s been hand lapped.
http://www.nosler.com/blog/news-and-articles/2016/2/24/custom-rifle-barrel-break-in-procedure
 

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I did the break in on one rifle back when I was younger and won't mess with it again. I did a fair amount of research when I got into custom rifles because I wanted to make sure I did everything right and came to the conclusion that it's not for me. I remember reading a barrel makers post on the subject and he said more barrels are damaged from the cleaning during a barrel break in. I will try to find a link.
 

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Neighbor had 4K+ of hot .260 rounds, most of the time in rapid succession and it still had not opened up at all. 1/4" groups. Guy who wanted to buy it had him meet him at a gunsmith to inspect and make sure the lands were still good. Guy said it had not even hit half life at all and was amazed it was in excellent shape for the round count.
 

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Discussion Starter · #12 ·
this is how Krieger explains it:

Because the lay of the finish is in the direction of the bullet travel, very little is done to the bore during break-in, but the throat is another story. When your barrel is chambered, by necessity there are reamer marks left in the throat that are across the lands, i.e. across the direction of the bullet travel. In a new barrel they are very distinct; much like the teeth on a very fine file. When the bullet is forced into the throat, copper dust is removed from the jacket material and released into the gas which at this temperature and pressure is actually a plasma. The copper dust is vaporized in this plasma and is carried down the barrel. As the gas expands and cools, the copper comes out of suspension and is deposited in the bore. This makes it appear as if the source of the fouling is the bore when it is actually for the most part the new throat.
If this copper is allowed to stay in the bore, and subsequent bullets and deposits are fired over it, copper which adheres well to itself, will build up quickly and may be difficult to remove later. So when we break in a barrel, our goal is to get the throat “polished without allowing copper to build up in the bore. This is the reasoning for the fire-one-shot-and-clean procedure. Every barrel will vary slightly in how many rounds they take to break in For example a chrome moly barrel may take longer to break in than stainless steel because it is more abrasion resistant even though it is a similar hardness. Also chrome moly has a little more of an affinity for copper than stainless steel so it will usually show a little more color if you are using a chemical cleaner. Rim Fire barrels can take an extremely long time to break in, sometimes requiring several hundred rounds or more. But cleaning can be lengthened to every 25-50 rounds. The break-in procedure and the cleaning procedure are really the same except for the frequency. Remember the goal is to get or keep the barrel clean while breaking in the throat with bullets being fired over it.
Finally, the best way to tell if the barrel is broken in is to observe the patches; i.e. when the fouling is reduced. This is better than some set number of cycles of shoot and clean as many owners report practically no fouling after the first few shots, and more break-in would be pointless. Conversely, if more is required, a set number would not address that either. Besides, cleaning is not a completely benign procedure so it should be done carefully and no more than necessary. - See more at: http://www.accuracysystemsinc.com/KRIEGER-BARREL.php#sthash.3ZnQxZhh.dpuf
 

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Yes, the tool marks in the throat is what you are actually "breaking in" but look at the finishes left from the modern cnc machines. Longrifles inc has posted some pics of their chambers on Snipershide over the years and they look amazing for not even touching them with anything to polish. We all know how far lathes and mills have come, look at it from the racing side of it. The quality and finish of the modern heads is impressive to say the least.
 

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Discussion Starter · #15 ·
Here's one link I was looking for. I still can't find the comment on the forums about people with cleaning rods doing more damage.

http://www.6mmbr.com/gailmcmbreakin.html
a good quality cleaning rod, and being very careful with the crown I would imagine will be fine.
Another twist, I had read an article where the crown of a rifle was intentionally beat up, and the accuracy wasnt affected by much....LOL

Like most things....the more you know the more complicated things get....:rolleyes:
 

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Very interesting. I for one have always been skeptical about barrel break-in. This article brings light to a reasoning that it should be done, especially on long range rigs. Thanks for posting.
this is how Krieger explains it:

Because the lay of the finish is in the direction of the bullet travel, very little is done to the bore during break-in, but the throat is another story. When your barrel is chambered, by necessity there are reamer marks left in the throat that are across the lands, i.e. across the direction of the bullet travel. In a new barrel they are very distinct; much like the teeth on a very fine file. When the bullet is forced into the throat, copper dust is removed from the jacket material and released into the gas which at this temperature and pressure is actually a plasma. The copper dust is vaporized in this plasma and is carried down the barrel. As the gas expands and cools, the copper comes out of suspension and is deposited in the bore. This makes it appear as if the source of the fouling is the bore when it is actually for the most part the new throat.
If this copper is allowed to stay in the bore, and subsequent bullets and deposits are fired over it, copper which adheres well to itself, will build up quickly and may be difficult to remove later. So when we break in a barrel, our goal is to get the throat “polished without allowing copper to build up in the bore. This is the reasoning for the fire-one-shot-and-clean procedure. Every barrel will vary slightly in how many rounds they take to break in For example a chrome moly barrel may take longer to break in than stainless steel because it is more abrasion resistant even though it is a similar hardness. Also chrome moly has a little more of an affinity for copper than stainless steel so it will usually show a little more color if you are using a chemical cleaner. Rim Fire barrels can take an extremely long time to break in, sometimes requiring several hundred rounds or more. But cleaning can be lengthened to every 25-50 rounds. The break-in procedure and the cleaning procedure are really the same except for the frequency. Remember the goal is to get or keep the barrel clean while breaking in the throat with bullets being fired over it.
Finally, the best way to tell if the barrel is broken in is to observe the patches; i.e. when the fouling is reduced. This is better than some set number of cycles of shoot and clean as many owners report practically no fouling after the first few shots, and more break-in would be pointless. Conversely, if more is required, a set number would not address that either. Besides, cleaning is not a completely benign procedure so it should be done carefully and no more than necessary. - See more at: http://www.accuracysystemsinc.com/KRIEGER-BARREL.php#sthash.3ZnQxZhh.dpuf
 
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