science or myth behind barrel break in ???

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Gale McMillan sold out 1987 also been a benchrest shooter since the 60's and knew all about barrel break-in. You can say lot of things when bottom line isn't going to be effected.

When Gales son's started rifle building business it was good till the deal about credit line etc and they lasted about 1yr and sold that business off last year so now all that's left is the stock business.

http://www.guns.com/2013/09/27/mcmillan-firearms-manufacturing-leave-mcmillan-family/
 
When I see top shooters doing barrel break in-That to me means something,alot more than the word of Mr Mc Millan.
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Here is the point I'm trying to make:

Gale McMillan WAS one of the top shooters in the world. He passed away a while ago--but he shot a one-hole benchrest record that has not been broken since--and I personally believe that the record will stand for quite some time.

And, not only was he a top shooter--he manufactured the rifles that some of the top shooters in his time used. I think it says a lot for his credentials.
 
I recall reading some old "JM Pyne" stories in John Amber's Gun Digest..supposedly loosely structured around Harry Pope and the like.I believe the stories sometimes mentioned heated disagreements among Pyne and his peers.

No doubt Gale McMillan was a world class barrel maker who knew his stuff.

I know Badger and Kreiger both advocated for a break in procedure.

I find it a stretch to question the integrity of both of these barrel makers in recommending break in.

Badger has been absorbed into a larger company,but I cannot see Kreiger recommending a procedure they don't really believe in to sell more barrels.

I have read Kreiger's explanation of barrel break in on their website,and it makes sense to me from the perspective of my experience building plastic injection molds.

The brief idea:

The barrel (premium) barrel maker has already made the bore.lands and grooves to an amazing degree of quality,and it is very unlikely the shooter can/will do anything to improve the work of the barrel maker.

Indeed,most anything done to the barrel by the shooter will detract from the maker's quality..Pretty much Mr McMillan's valid point.

However,between the barrel maker and the shooter is chambering.The chamber reamer cuts across the nice lapping of the barrelmaker.The chamber reamer cuts an interrupted cut across the lands,that will drag,however slight,some amount of burr

The throat/leade are cut by the reamer based on the pilot/bore fit,and however small the clearance /mismatch,etc of perfectly transitioning from the throat to groove dia geometry to blend to bore dia,most of the time there will be some very small imperfections burrs,or cutter marks.

Gale McMillan does not make those,maybe I do with my brand new Elliot or PTG reamer..

The theory,as Kreiger explains it,these imperfections I put there when I chamber his barrel leave some copper shavings or dust on the bore surface after firing.

Shooting subsequent bullets over these bullet jacket bits wedges them between the bullet and the bore..

It is easy for me to believe its better to wipe the bore clean between shots for a while.

I have also seen how a low pressure use of fine glass beads will take the burrs off and blend very intricate,fine machining that is not practical to deburr by other means.I can envision firing the rifle serving as the media blasting to take the sharp imperfections off the shoulder/lead area.

Then the bullet jacket gets formed rather than cut,no more copper chips.

I also know,from personal observation,that when a brand new,surface ground,precision mold is hung in a mold press....If something about the workmanship or molding process leaves plastic bits or nozzle drool on the faces of the mold plates,when the mold closes,that material,while soft,is not compressable.It will impress into the steel of the mold plates.BTW,the mold plates are an alloy similar to 4140 at about 30 Rockwell"C",+ or minus.

Those plastic bits will soon have the parting line looking like it was flogged with a logging chain.

That's my take on it,and I practice break in with that process in mind.
 
OK... so the after chambering I understand... I having shared building with my local builder buddy, I know that some chamber reamers are more prone to chatter ( I think it depends on fit of the pilot, & the number of flutes... & possibly the angle of cut on the flutes )...

however... any roughness or loose chips should probably be removed, when brushed prior to shooting, after the chamber is cut... it shouldn't require soft copper jacketed bullets to remove loose chips, & if there is enough burr, again, I'd think it would take more than a handful of bullets to "iron out" the imperfections ???
 
Shooters are strange people. When you get to the level of world records everyone has gear and methods that can win the day. Some might not drink coffee for a day or so before the shoot, others will have a cup sitting on the bench. Monkey see, monkey do is an actual method of mental prep. They all have the same actions, same barrel, same everything. Some break in the barrels and others don't no matter who made the barrel or what they said do with it once they sold it. Shooters do stuff, some of it based on science and some based on nothing, and for them it works.
There is no answer without a double blind study of the subject.
 
Magnum wheel...Chips must be removed through the whole process of chambering,I'm not talking about barrel chips.

Assume before the first shot is fired the barrel is immaculate.

No disrespect intended,look back on any experience you have cutting steel...even drilling a hole.Pretty much,you can count on a cutter will leave a burr.

A brand new,finest quality end mill will leave a burr if you make a cut with it.

If you put a shaft with a keyway in it (like a rifling groove) in a lathe,use as fine and sharp of a lathe cutter as you can stone,and turn an interrupted cut across that keyway,you will get a burr .

Even with coolant on a surface grinder,of of a square edge,you will get a burr.

Im not talking about chatter.Put a piece of steel in a vise,cut across the top with a file till the top is a clean cut.Now,on the far side from you,drag your thumbnail across the edge.the burr will scrape off thumbnail.

It works as a cutting edge.I make inletting scrapers by taking a piece of approx. .025 feeler gage stock and grinding across the end.Cuts nice!

I agree with your statement that any chips should be removed before firing,and,IMO,that is the point of running a patch between rounds.Wipe out the copper flecks instead of shooting over them.

Remember we are talking about just the throat/leade having any imperfection.
Powder blast plus the bullet wiping by will in time reduce the burr.

Please understand,I've never made a barrel,never shot a record group,and do not suggest I am an authority on this topic.

I can take what Kreiger has to say on this topic,look at it through the experience my eyes have,and say "Makes sense to me"

I have tried to describe how perhaps it may work.Form your own conclusions.
 
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I get that part... but if there is enough of a burr, that the bore brush won't pop it loose, with an initial cleaning after chambering, I'd expect the burr to either flatten into a groove, when firing the 1st shot... with a tight fit ( as should be expected with any jacketed bullet ) that burr will likely be flattened down far enough, that the bristles of the brush will not lift it... so I don't know how to remove that flattened steel burr in reality
 
Like a lot of topics on this forum.....and pickup's......It's Ford versus Chevy with a smidgin' of Dodge tossed in to keep the discussion lively!,:rolleyes: I have never been able to tell the difference, but to confess, I follow Gale McMillan's thoughts. But then I only have experience with Douglas barrels!!:)
 
I agree with the above post. If you want to break in, break in. If not, don't.
I think its a waste of time. Others swear by it. People also swear by all this goop you pour in your motor oil that the FTC has fined the companies for marketing under deception. People used to drop their last dime buying snake oil. I am not degrading those who do break in. I am simply saying that if one wants to believe in something, they will believe come hell or high water.
 
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Whether lead bullets or copper-jacketed, ALL shooting burnishes the barrel. That's gonna happen whether you clean very frequently, occasionally, or hardly ever. The barrel will get polished.

The way I figure that all this "break in" got into the mainstream was that somebody who'd heard from Gale's compadre or a customer of his went to work for a gun company. In chit-chat at work, the subject came up. Okay, so it sounded like a good idea and was eventually added to the owner's manual.

People move around in the industry and "everybody knows" becomes part of the common wisdom. Same sort of cross-pollenization between Ford, Chrysler and Chevy in the old days.

I tend to give heed to folks who have accomplished the sorts of "best ever" achievements. Credibility earned from BTDT. So, I'm in Gale's camp.

I just don't see it as very important, one way or the other. For some fifty years I managed quite a few half-MOA groups without knowing about barrel break-in.

But, like I said earlier, folks oughta do what they think is right and not worry about what other folks do or don't do.
 
But I kept it, and gave it a thorough break-in, removing copper and carbon every shot for twenty rounds, then every 5 shots for twenty, then every ten shots for forty - and every twenty rounds thereafter.
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OK, so I'm trying to follow this logic- please explain what I'm missing or where I'm incorrect...
Shoot, clean the copper out of the imperfections in the leade. So, that leaves you where you started, or "where you started", less a little wear in the machining imperfections that exist. Right? It has to be one of the two, no other mechanism is acting on the barrel.

Seems logical you're not laying down copper jacket, only to be removing it over and over again...Like doing the same thing over and over, and expecting a different result.

Unless you're "removing", "wearing down", "smoothing-out", whatever you want to call it, the imperfections. Seems logical that's not only the case (friction, certainly), but also the objective.

Get rid of the imperfections. They're either hand-lapped out, or as Bart said, the shooter is simply making it the way it should have been in the first place.

I fail to see how removing copper between shots, either extends barrel life, or improves accuracy. Copper fills the imperfections. Smooth leade...

Will the imperfections wear away faster with the copper removed? I'd agree probably so... but if you follow this logic, you're wasting barrel life as Gale M. says because you're just wearing out the barrel by altering the process that would take place anyway if just left alone.

Most barrels shoot better with a layer of copper fouling, which leaves me in the camp of "just shoot it" (not abuse it).


As to your Mosin-Nagant, MANY things affect accuracy, and bore condition is only one of them. I'd bet I could put that action into an aftermarket stock, epoxy bed it, and shrink that group size significantly unless that bore is a sewer pipe- and if that's the case it shouldn't even be used as a basis of comparison. Tough enough to bring 100 year old rifles into a discussion comparing them to modern precision rifles.

Cut and re-crown the barrel, and free-float it along with bedding it, and it just might shoot 2-1/2"- 3" at 200 yards as both of mine do.
 
I just read an article in Rifle magazine where the author did some testing on a factory barrel with chatter marks and a hand lapped custom barrel costing several time as much.

The results confirmed what I already knew....Breaking in the barrel did nothing for accuracy. Both barrels shot about as well as one another. The custom barrel was easier to clean but there was no indications that having smooth lands and grooves made any difference in performance.

I've tried it and came to the same conclusion. But hey, it's your weapon and your money....do with it what you will.
 
[John's 2 Cents]If your bore is rough it will accumulate jacket/copper fouling faster and if the fouling gets really bad, you'll see an accuracy decrease. Making the barrel smoother will help eliminate that issue.

Barrel break-in can help make a barrel smoother faster than normal use will.

The important things to keep in mind are:

1. Not all bores are rough or need to be smoothed.
2. Even bores that are rough, may not accumulate metal fouling fast enough to cause a problem--especially for low volume shooters.
3. There are other (better/faster/more effective) ways to smooth rough bores besides barrel break-in.
4. Generally speaking, cleaning the bore thoroughly (getting rid of all fouling--jacket fouling included) after every range session will have the same effect as barrel break-in. It will just take longer. Unless you're noting a really rapid accuracy drop-off due to jacket fouling (i.e. you have a really rough bore), there's almost certainly no need to do a special break-in process.[/John's 2 Cents]
 
My experience has been that i have not noticed a decrease in accuracy in barrels that have been broken in, compared to those that haven't. Does that mean that you never need to break in barrels? Nope, it just means that i'm not a good enough shot to worry about it. :D
 
appreciate the civil discussion... I have several rifles to shoot this spring, that are either new / unfired ( like my JOC Winchester, & a NOS Remington 700 - 100th anniversary of the 30-06 ) or several custom rifles like my newly completed 6.8 SPC Remington 700... also have a purpose built long range rifle in 6.5-284 if I find time to finish up the stock yet this winter... anyway... I've never "broken in" a rifle barrel yet... so was wondering if I was missing something...

maybe the better way to look at this is to do 1 fouling shot, & then a 4 or 5 shot group... if the group is not as expected, or the bore looks more fouled than expected, I'll thoroughly clean, & then try a modified "break in" & see if either the groups or the fouling get better ???
 
without trying to get in a peeing match... to someone with a bore scope... it would be nice to see some pictures before, a couple at various stages during, with a round count & after break in, to show that copper bullets can smooth out rifling imperfections...

otherwise I have a hard time believing a hand full of copper bullets & a few passes with a brush would remove the "waves" visible in the bore pictures posted previously
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I would have a hard time believing a hand full of copper bullets & a few passes with a brush would remove the "waves" visible in the bore pictures posted previously, too.

That's why I never said or implied anything of the kind.

Without trying to get in a peeing match... - How about responding to what is actually said, instead of arguing with yourself over something that you made up?

Since nothing other than copper-clad bullets going through the bore were there to smooth out the roughness to some extent, I think we can use simple logic and safely assume that those copper-clad bullets were the culprits.

One time I needed a hole in a chunk of 1/4" angle-iron on a boat trailer... We didn't have a drill on hand, but we did have a Browning Stainless Stalker in .300 Winchester magnum. - A bullet from the Browning, made of lead covered with copper did a fine job of drilling a clean hole right through that steel.

When we talk about what goes on within a rifle barrel, it serves us well to keep heat, pressure and velocity in mind. A chunk of copper thrown by hand at steel will have little if any effect... A chunk of copper traveling at high speed though, followed by high pressure, very hot gasses is another story.

If you dig around for it ( I won't do it for you ) you can find videos of very high pressure water jets cutting right through steel in an industrial process that came out a decade or two ago. Hot, high velocity gasses are what eats out the throat on magnum rifle barrels... If gas can do that, imagine what copper-clad lead can do, despite being at a much lower temperature.

9-11 truthers insist that steel cannot be melted or weakened by fire... This kind of misconception is, regrettably, much more common than it should be. In the case of the 'truthers', the public school system failed them by teaching them what to think, instead of teaching them how to think.
 
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PVL... sorry if you thought my comments were a personal attack, as it was not intended, & in fact, you are not the only poster on this thread that said they had a bore scope :) you are however the only one that posted pictures, which I do appreciate... your last response seemed to me, to be a personal attack... I'd like to keep these discussions civil, & thus keep the thread open for discussion...

... yes I'm well aware of bullets shooting holes in steel, & also understand the theory behind water jet cutters...

... however there is a huge difference between a bullet smashing a piece of steel at 3000 fps at any set distance, & a bullet sliding along a groove that it's nearly been in contact with to begin with... I'm sure the water jet cutter works at best efficiency, when spraying directly onto a piece of steel, & probably won't cut efficiently at all, if just sprayed across the surface paralel with the steel...

... & in fact, it could be possible that the gasses do as much to remove the burrs discussed during chamber reaming, as the bullets do them selves, as throat erosion is generally thought of being caused by the gasses... & since the discussion is "break in"

the basis of my question is...how are those few handfulls of bullets with a few strokes of the brush in between, any different from several typical range sessions with cleaning in between???
 
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The trouble with all this theory is that it's all virtually unprovable. You'd need a whole bunch of barrels as close to identical as possible. Just buying "identical" guns wouldn't be enough. You'd have to make sure the barrels, chambers, leade, rifling, internal surfaces and dimensions, were as close to identical as possible. I think you'd need at least 20, broken into 4 groups of 5. Then you'd need identical ammo, that's easy. Then you'd have to do the experiment, which would require hundreds of rounds through each gun, since you'd have to shoot statistically significant groups and at various ranges. You're talking probably 10,000 rounds.

Otherwise, we're left with speculation and comparisons between non-like situations, a lot like saying it's cold in Fl because I'm in NY and it's cold here, or I had a Honda that was junk so all Hondas are junk or my Saturn was awesome so all Saturns are awesome. (I'm sure somebody had a reliable Saturn, somewhere. ;))
 
I'm no expert, but here's what I see.

Some barrel experts insist break in is absolutely necessary.

Some barrel experts say it is not.

There are numerous break in procedures. Many ideas on how to do it rather than one universally accepted formula.

All of this tells me there is no definitive answer to the question on whether it is required. If there is no definitive answer, it's probably no.

My answer is simple. If YOU think it helps, then do it.

PS: I have agree that it would take thousands of rounds for a copper covered bullet to wear the tempered steel of the barrel. Shooting, 10, or 100, would have an effective influence of zero. So shooting a small number of rounds to smooth or polish the steel of the barrel strikes me as myth.
 
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