Article on barrel manufacturing

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Obtunded

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Dr. Geoff Kolbe (PhD in engineering) is the head of manufacturing and design for Border barrels in the UK. He is a world-renowned authority on barrel manufacturing.

He wrote what is almost a treatise on barrel-making and it has been in circulation for a while. His article was updated last year and has more photos. It is a very good read, and I think adds a measure of authority to opinions regarding many facets of shooting that are frequently discussed on this forum.

Krieger and Border both produce button and cut rifled barrels. Kreiger markets theirs under the name "Criterion" whereas Border markets them under the brand "Archer".

Border barrels has a very different approach to barrel break-in, and I struggle with it, but it goes to show how opinions on this subject alone are widely varied even amongst industry experts...

Here is the article...
 
Interesting read.

"Break in or shooting in" always has theory involved. I believe Dan Lilja is of the same beliefs as Border Barrels...

Here is what Border Barrels say:

There is much discussion about 'shooting in' a barrel.

A few words on why 'shooting in' a barrel is necessary. No matter how well lapped or how finely finished the internal surface of the barrel is, the first few bullets down the barrel seem to leave a significant fraction of themselves behind as heavy metal fouling. A subsequent bullet shot up a barrel with heavy metal fouling will tend to press that fouling into the barrel causing dints and roughness in a bore that the barrel maker has gone to a lot of trouble to make smooth and even. So it is important to get all that metal fouling out before shooting another bullet up the barrel.

But lets not get another 'should we or shouldn't we thread' going... :D ... thanks for posting the link...
 
Exactly

guntech said:
A few words on why 'shooting in' a barrel is necessary. No matter how well lapped or how finely finished the internal surface of the barrel is, the first few bullets down the barrel seem to leave a significant fraction of themselves behind as heavy metal fouling. A subsequent bullet shot up a barrel with heavy metal fouling will tend to press that fouling into the barrel causing dints and roughness in a bore that the barrel maker has gone to a lot of trouble to make smooth and even. So it is important to get all that metal fouling out before shooting another bullet up the barrel.

QUOTE]

what my thoughts have always been on breaking in barrels. I will never deviate from my rituals.
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guntech said:
Interesting read.

"Break in or shooting in" always has theory involved. I believe Dan Lilja is of the same beliefs as Border Barrels...

Here is what Border Barrels say:

There is much discussion about 'shooting in' a barrel.

A few words on why 'shooting in' a barrel is necessary. No matter how well lapped or how finely finished the internal surface of the barrel is, the first few bullets down the barrel seem to leave a significant fraction of themselves behind as heavy metal fouling. A subsequent bullet shot up a barrel with heavy metal fouling will tend to press that fouling into the barrel causing dints and roughness in a bore that the barrel maker has gone to a lot of trouble to make smooth and even. So it is important to get all that metal fouling out before shooting another bullet up the barrel.

But lets not get another 'should we or shouldn't we thread' going... :D ... thanks for posting the link...
Click to expand...

I don't understand how a softer metal (copper) can dent a harder metal (stainless).
 
I read this article about ten years ago he has added some very good information.
I got interessted in making barrels quite a while ago and had ordered a book and video from brownells[bill webs barrel making machine],I started making it about 10 years ago and never completed it I have most of the frame parts made and the headstock.
I just seen a few things reading through this and a few pictures that gave me a few ideas ,maybe I will start working on this again if I can find time.
 
It does indeed provoke debate on some topics... button vs. cut, barrel break in, but most interestingly i detected what I perceived as a dismissal of hammer-forged barrels.

Tikka and Sako do indeed use HF to make barrels, and I would argue they are the most consistently accurate factory barrels I've used by a large margin.

As to shooting-in, Intellect and experince certainly add credibility, but they only provide the ammunition for the creation of a hypothesis. In the face of contradictory experiences, it only demands that such hypotheses undergo proper proper quantitative testing. Interesting how these barrel manufacturers seem to dogmatically eschew this evidentiary paradigm in favor of prescribing rituals of intuition.

I don't profess to be any more or less correct in my approach (or lack thereof) to barrel break-in, I merely assert that since nobody has ever bothered to test their hypotheses in anything other than an anecdotal way, there is no scientific proof that break-in is any more or less helpful - or deleterious - to the lifespan or accuracy of any barrel.
 
speers said:
Take your favorite knife and try and peel the copper jacket off a bullet with it and you'll soon find out :p :ar15:
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I don't think any of my knives are made from the same stainless steel that the barrels are made from.
 
KDX said:
I don't think any of my knives are made from the same stainless steel that the barrels are made from.
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Good point, but your knives do dull on things like wood and so on which are softer then steal right, much like a copper is softer then steel used to make a barrel. Just because its softer dosen't mean it wont show wear ....
 
Obtunded,
Great sentence! It's not often I read of anybody eschewing an evidentiary paradigm on these boards; whether or not it's to prescribe a ritual of intuition. ;) Regards, Bill
 
Yes Bill, I should have known better. I kept a set of magnetic letters, animals and fruit on the side of my camper van to try and explaing things to Dreger, and he even had trouble with that.

See #### shoot. Shoot, shoot shoot.
 
speers said:
Good point, but your knives do dull on things like wood and so on which are softer then steal right, much like a copper is softer then steel used to make a barrel. Just because its softer dosen't mean it wont show wear ....
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So if there is a burr on a land it should eventually be worn smooth by the passage of bullets?
 
Obtunded said:
... button vs. cut, barrel break in, but most interestingly i detected what I perceived as a dismissal of hammer-forged barrels.

Tikka and Sako do indeed use HF to make barrels, and I would argue they are the most consistently accurate factory barrels I've used by a large margin.
Click to expand...

Read in a Precision Shooting Magazine article that hammer forged barrels done correctly on a perfectly set up hammer forge, with a perfect mandrel that incorporated a chamber on the mandrel could theoretically produce the best barrels. Unfortunately very few manufacturers care to keep their machines tuned and toleranced properly or use quality mandrels and consistent proper use of the hammer forge.
 
Barrel break in will always be a controversial subject. Here is an article by Dan Lilja with his thoughts. Essentially he feels copper has to be removed so powder residue can build up on the bare steel. The residue coated steel is less vulnerable to continued removal and build up of copper. Further he believes over cleaning with an abrasive removes this coating and makes the fouling worse.

Barrel Fouling - Dan Lilja

My personal believe is that you have to remove the copper that collects in the low spots in the steel. That copper protects the peaks of the steel, and prevents them from being worn down. When you get the copper out, then the peaks wear down and the surface becomes smoother without getting too smooth. So, by getting the copper out after every shot you let the barrel smooth out faster than if you just shoot it.

I would suggest that no matter what you believe about how break in happens, there is absolutely no doubt it does happen. All you have to do is check for copper. A new barrel will almost always show copper even custom hand lapped ones. But, after 10 shots it may be totally gone, and a little later barrels are good for 50+ shots with no fouling. And some barrels never break in. Probably just way to rough of a finish to smooth out.

On hammer forged barrels I have to agree with Border. It has to be the absolute worst way to make a barrel. You take a piece of pipe, put a mandrel with reverse rifling on it inside the pipe, and then hammer the crap out of it from the outside. You get a piece of steel just loaded with residual stress which are worst on the outside diameter. Those stresses are just waiting to warp the barrel when heated. Yes, I know they are stress relieved, but they can't be totally stress relieved or they would have no strength.

Testimonials about Tikka and Sako does nothing for me. I will put my factory button rifled Savage barrel up against either of them any day. Plus I don't think the line up at Tikka to buy hammer forged barrels for custom guns is very long.
 
Most of my barrels never see copper, cast only, but I always break my barrels in by cleaning after every shot for 20 or so and then cleaning every 2 shots for 40 or so and tapering off after that. I have also found that cut rifled barrels seem to be most accurate for me, but they all get the same break-in.
 
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