Barrel break in - Yes or No

[NBK]

In my quest for knowledge regarding precision long range shooting and precision long range gun information I have read many many articles regarding barrel break in. I for one, was a huge proponent of proper barrel break in. But the more data I gather and the more discussions I have with folks who no more than I, I have succumbed to the inevitable. My new opinion is that barrel break in is not necessary and more or less a waste of time and money (and barrel life).

I would love to hear opinions from others. I recently changed my mind regarding break in and may even have some posts on this forum contradicting my current opinion. Maybe I am a slow learner.

The rifle I am currently building will incur no break in. So be it...

Below is a great barrel break in article written by Gale McMillan. There are many but this article is a bit crass and raw and let's face it, Gale is considered by many to be an accuracy and barrel pioneer.

Again, what are your thoughts?

http://www.accurateshooter.com/technical-articles/how-to-break-in-a-barrel/

 

[msteiger]

NBK I have noticed that many people believe in, and recommend, barrel break-in. I have always kept my mouth shut. I have never seen a scientific explanation for break-in, and I have thought long and hard if I could even make one up. I might be willing to believe, through a variety of factors, that some rifles 'settle down' after a number of shots. But the frequent cleaning between those initial shots strikes me as superstition.

I once read a rifle manufacturers comments on break-in. He said he included break-in instructions with his rifles because he was tired of people asking for them. But he thought it was a waste of time.

Add to that these articles by David Petzal, rifle editor for field and stream. I have not read any living writers who were more knowledgable about rifles and he also poo-poos the notion.
http://www.fieldandstream.com/pages/great-barrel-break-fad
http://www.fieldandstream.com/blogs/the-gun-nuts/all-about-rifle-break-in-group-testing-and-the-relevance-of-quantum-physics-in

 

[TaftHunter]

if you mean by shooting at coyotes, then yes I do break my barrels in

 

[Bonejour]

All I know is the groups I get when I shoot. I have broken in three rifles. None of them shot as well out of the box as they did after breaking in. Maybe they needed the fouling that I wouldn't allow during the break-in period, and now that I let them foul a bit between cleanings, they are better off. That would be an interesting experiment, but none of these three articles reports on that sort of comparison. As far as wearing out the barrel, has anyone in this forum ever worn out a barrel by firing too many rounds through it? I mean, come on: we buy rifles because we want new toys, not because our old rifles wore out.

 

[msteiger]

I was wondering if anyone could/would say they had better accuracy after a break in. I wonder also about getting used to a gun. It would be relatively simple to do a controlled native accuracy vs # of rounds test, using a sled. But the results might only be for that gun or model.

I will have to look for scientific studies. I'm sure the military has looked at it.

 

[Bonejour]

I wonder also about getting used to a gun.

Amen to that. Lots of variables other than the barrel itself with a new rifle (and scope): cheek weld, parallax, turret accuracy....
I have focused on barrel care for the first 40-50 rounds with each rifle. If I knew that were not an issue, it would be a great relief.

 

[Bonejour]

Let me ask a question: What is the objective of breaking in the barrel?
My understanding of the break in process is to polish the bore gradually so that it can go long periods of repeated firing without losing accuracy due to excessive fouling. Manufacturers' claims of "Out of the box accuracy" don't really address this longer term view of breaking in because a barrel can be accurate but still be prone to quick fouling. I suppose at a minimum, a barrel should be cleaned at least when you start to see fouling. Thoughts?

 

[MJB]

I don't know about barrel break in but the Final Finish from tubbs really makes a big difference in my M70 60's 70's 80's & sav 111ss 04'

 

[NBK]

Most new custom barrels are hand lapped so not necessary. But there are many different camps on this (this is why I asked for opinions). And Krieger actually has a blurb on their site regarding break in below:

BREAK-IN & CLEANING:
With any premium barrel that has been finish lapped -- such as your Krieger Barrel --, the lay or direction of the finish is in the direction of the bullet travel, so fouling is minimal compared to a barrel with internal tooling marks. This is true of any properly finish-lapped barrel regardless of how it is rifled. If it is not finish-lapped, there will be reamer marks left in the bore that are directly across the direction of the bullet travel. This occurs even in a button-rifled barrel as the button cannot completely iron out these reamer marks.

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.

 

[MJB]

Custom barrel........whole other game......better be badass after break in.......if recommended by the manufacture.....lol

 

[ilovesprig]

Good Gawd!..........How have I ever killed anything with my old Mod 70?.........

 

[msteiger]

John I was going to post that text from Krieger. At least it's an explanation. I'm still looking for scientific evidence, but coming up empty.

 

[NBK]

JP has a couple of rifles that have shot 10th of an inch groups from the first 5 shots. He has 40 or so rounds through one of the guns and has not cleaned it yet.

 

[msteiger]

Holy mackerel

 

[Lungpopper]

Why is the micrometer reading less than the bullet diameter of .264?

 

[El Matavenados]

Why is the micrometer reading less than the bullet diameter of .264?

It was probably zeroed at the bullet diameter, so that no math is necessary to see the final group size.

 

[NBK]

Why is the micrometer reading less than the bullet diameter of .264?

It was probably zeroed at the bullet diameter, so that no math is necessary to see the final group size.

What he said ^

 

[Bonejour]

Math? I think "holy mackerel" pretty well sums it up.

 

[stikbrandon]

Awesome thread guys