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How are barrels regulated?

If bending is involved, how is the strain on the welds relieved?

Hi,
I don't think modern barrels have welds. The barrels are bored, I believe. On some of the Parkers I have owned, I thought I could see that one barrel was "Englished", or bent slightly to parallel the left one by looking through it. However, I asked Oscar Gaddy about this and he had never noticed it.

Bm,
Barrels on most production sxs guns were/are assembled to established dimensions of convergence. That includes some of the pretty pricey stuff.

How the developed the "established dimensions" is usually thru shooting. Then those dimensions would be applied to production guns by either providing assembly tooling or by simply providing the assembler of the barrels with the dimensions.

The 'how' of actually assembling and solding barrels/ribs will really surprise you. Drew has a website dedicated to gun knowledge that has an article I put together on the traditional method of bailing wire and spacers and pro gunsmith has an article where he made an assembly fixture. Hopefully Drew will drop in and provide the link to his site.

PS
Jim is correct, barrels are generally bored from solid bar. An alternate method is to drill a short fat bar and hammer forge it to the nearly final shape in a special barrel making hammer forge that looks like a big lathe.

Really old methods were to forge weld a series of strips of metal over a mandrel. This was the method for "twist steel" and "damascus" barrel making. Drew also has articles on this as well as PeteM on his website.

By welds I meant the seams between the barrels and the ribs.

Bending the two barrel from one side to the other would stretch the near barrel and compress the far barrel, putting strain on the seams

BM,
The "seams" between the ribs and barrels are generally soft soldered with 60/40 tin/lead solder. Alternatively, they have been soldered or brazed using various higher melting temp mixtures containing either silver or bronze or both.

The barrels are simply pulled together to get the predetermined dimensional convergence (angled together) based on earlier shooting experience. Spacers are put inbetween the barrels at a few locations where the bailing wire will be used to bind the ribs and barrels together to prevent them from bending the barrels inward excessively when the bailing wire is twisted up tight. Then the whole mess is heated with a torch to solder everything together.

Here's the link to the web article.
http://www.picturetrail.com/sfx/album/view/18691676

Bushmaster,

I know you are asking about the ribs, etc. These are some pictures of earlier methods of barrel making.

Here skelp is hammer forged around a mandrel.




This is from a patent for a rolling mill that can create barrels from sheet stock.


This is damascus being wrapped around a mandrel


Very few shotguns are individually adjusted for poi. Holland & Holland has an excellent video that shows them hand adjusting barrels while at a patterning board. This process is reserved for only the very best grade of guns. Early on barrels, made from solid stock, were being brazed.
http://www.gunmakersrow.co.uk/

Pete

The one double rifle I saw being regulated was done with the ribs off the gun.

I believe the H&H DVD shows a shotgun being shot for regulating without the ribs. But some here and maybe it was Kirk Merrington (I could be wrong on that) that told me the ribs will influence the POI and should be installed and removed for regulating.

Chuck, the shotgun in the H&H video was complete with ribs in place. The only "regulating" done was for pattern only. They did show the POI regulating of a double rifle and that did involve loosening the rib and adjusting the barrel wedge at the muzzle. I'm inclined to go with what Jack Rowe recently told me: shotgun barrels were not regulated for POI unless something was badly amiss. He pointed out how much POI could move by just simply varying the loads. I loved his closing comment, "my goodness, it's a shotgun.....just shoot it!"

Joe,
It's been a yr or more since I watched the video and now it's been with a friend for most of that time. I need to get it back from him.

I understand what Jack was trying to say, but once you've taken a set of barrels appart and are putting them back together, you get really concerned about regulating them for not only the convergence but the elevation relative to each other.

When I did that 28g conversion on a 20g LC, the convergence was way off when the muzzles came together, then the POI relative elevation was also somewhat askew even though carefully aligned on the outside of the barrels.

I'll not call any names but the guy I watched is a famous American double rifle builder. I'm almost positive the ribs were off when he test firing the gun....There was a wedge welded or soldered in place.

I'd agree with that when talking about American made SxS's but don't think I would when talking about English built guns.

jOe I think Joe Wood and Jack Rowe are both wrong. But I want to point out that Mr. Rowe is an Englishman immigrated to America after he served his apprenticeship and much of his adult working life in the Birmingham gun trade.

But I still am looking for a paragraph I read years ago about regulating barrels. Haven't found it yet but I am still looking.

Best,

Mike

Chuck H:
Thanks for the insight as I've been chasing this rabbit for some time and there just isn't that many folks or sources of information on tube making. The "alternate method" may go a long way in explaing the translated term "barrel drawer" and mechanized barrel drawer if I understand correctly. In the mid to late 19th century job descriptions around tube making were tube makers(of course), master borers, polishers, grinders, etc. I too thought the blanks to have been bored or bar steel somehow forged. Both would have had some waste. The term "rough forged barrels" surfaces from time to time especially when associated with importing tubes and the Baldwin Brothers, who case was upheld due to the fact that the Whitworth tubes were "forged", which may have been due to the fact of the "alternate method", and allowed them to be on the "Free List".

If I have my numbers correct, even today Benelli's circle of error for POI is 9 inches(+/- 4.5"??) so I would say POI was lower than pattern in the overall scheme of things. I'm curious if Sauer addressed POI.

Kind Regards,

Raimey
rse

Mike, one question: where would a small Birmingham maker shoot his gun? Go to the range then back to St. Mary's? Back and forth? Comm'on. Jack mentioned that he only remembered Scott and Greener having an area available for shooting. I don't see why y'all think a gun cannot be lined up without all this rigamaroe. Heck, I've boresighted a whole lot of rifles to shoot within an inch at 50 yards. No big deal at all. What's the difference with a shotgun? And what good is precise POI regulation going to do if there's the slightest change in cartridge from that which was used to regulate in the first place?

Also, if it was a regular practice, don't you think there would be a lot of information about it? Nada....zip....zero.

Oh, while we're at it: how are you going to regulate elevation after the fact? Put on new ribs?

P.S. Being snowed in all day is making me grumpier than usual. And my quail are having to stay outside in all this ice!

Found a good article on hammer forging barrels from Precision Shooting

http://images.google.com/imgres?imgurl=h...sa%3DN%26um%3D1

Here's what W. Greener had to say about joining barrels in his 1835 book (Peter Hawker wrote the introduction):

ON PUTTING DOUBLE BARRELS TOGETHER.

The art of putting double barrels together seems to be but little understood, even by the first makers. It is a rare occurrence, indeed, to find double barrels properly put together, having neither too much nor too little inclination at the muzzle. I shall, therefore, take the liberty of making a few observations on this very important point; also, on the proper elevation of the rib. The trade have to thank Joe Manton for this, as one of the best inventions he ever brought forward. Were proper attention paid to the construction of these ribs, they would be invaluable, yet we every day see them bungled by blockheads in a way to make every judge of good work wish the bungler in Siberia.

Having then got your barrels ready to put together, and cut to the length you intend, it remains to be determined what inclination they should have. Be they long or be they short, they should, to be perfect, come to a point at a given distance, if for general sporting. If, however, you are putting together a large pair for wild fowl shooting, the inclination must be altered to suit the greatest distance to which it is intended the shot should be driven. There is a great diversity of opinion as to the proper inclination of a pair of double barrels. It is needless to state the precise distance at which the converging lines drawn from the centre of each barrel, and indicating the inclination of the barrels to each other, should come to a point. If we take the point of convergence of those lines at 2 1/2 yards, it will follow that at 40 yards each barrel, were it fixed in a vice, would throw the centre of its charge six inches on the opposite side of the mark, or body fired at; but if the gun be fired from the shoulder, the recoil will invariably cause the gun to swerve outwards, so that at that distance, she will never fail to throw her shot in a good direction for the mark or bull's-eye.

The subject may be understood by the following observations. All tapering substances, when laid together, were the taper extended, would come to a point at a certain distance. Gunbarrels are made to taper towards each other, and some more than others. To make them uniform, it requires that they should be reduced or flattened to allow the thick or heavy end to joint closer, to allow that point of convergence to be extended to a greater distance. If then, we take two barrels, two feet eight inches long, and having a solid substance of metal at the breech of 3/16 of an inch each, and is 1/16 at the muzzle; it requires the difference 4/16 to be multiplied 45 times (there being that number of lengths in 40 yards) to ascertain what distance the points of the different lines are from each other, which will be 11 4/16 inches, or 5 10/16 from the centre or line of sight. If you wish to reduce it from the centre, you have to join the barrels so much nearer at the breech ; or should the inclination be too little, the muzzle must be jointed closer. As, however, all guns are now made very heavy at the breech, they very seldom require any closing at the muzzle, though it is customary to do it, and to a great extent; but it is owing to the ignorance of the nature of shooting.

Having satisfied yourself that your barrels are set correctly, the next thing to ascertain, is the proper degree of elevation. Different lengths require a difference in the height of the rib. A greater height is also required for a person accustomed to use a crooked stock; and less height for one accustomed to the use of a straighter one ; and so on. Few barrels are to be met with in which the elevation is sufficient; a species of innovation much practised by gun makers of the present day, whatever merit there may have been in the original invention, there is none in " the improvement," as they term it. Take any of the modern barrels, and calculate what is the real elevation of them, and you will find it is not equal to the distance that charges will droop at 40 yards, when we consider the very large charges of shot that many are accustomed to use, without a corresponding quantity of powder. It remains then to be decided, what elevation a gun should have for that distance.

I have tried the experiment some hundreds of times with guns of all descriptions, both with a rest and from the shoulder, though standing as firm as possible ; and by turning quickly round, and firing (as I might do were a bird to spring in a situation where I could get only a snap shot) against targets, such as are used in military ball practice, being about six feet high, and by means of which you could perceive where the body of the shot had struck. I have also fired against the steep sides of those beautiful sand banks of which we boast on our own immediate coast, and on which, from their smoothness, you could tell every shot that had struck them. Those sand banks I found much superior to sheets of paper for trying guns, the marks being all visible at once, so that it is easy to define the outside limits of the charge. As to the last method I have tried, no one whatever has, for the time I have had an opportunity of trying it, fired more shots, or, as it has been told me, wasted more powder and shot by firing on the water, both at living and dead marks. To sum up all, my conviction is, that almost all guns charged, as it is the custom, with heavy charges of shot, droop full twelve inches at forty yards, though by using small charges of shot you will find them to be thrown much more correctly than the heavy charges ; so that it is possible to make a gun too high on the rib for a shooter that thinks more powder and less lead preferable to much lead and little powder, for believe me nothing is more injurious to the shooting properties of any gun than too great a weight of projectiles. Powder may be compared to the strength of a man. Give him a stone four pounds weight, and desire him to throw it—mark its flight; give him one half that weight—attend to its flight; one will cut a segment of a circle— the other a parobolic curve, keeping a direct line until its initial velocity is gone, and then cutting a part of a circle, though it has gone twice the distance, and with twice the force; thus proving, that if weight is to be thrown with only a certain propulsive force, there must be elevation to carry it to the destination intended, though at a much less speed and force than if that weight were one half less. Thus a gun maker can only construct the elevated rib by guess, if the gun be not ordered, or the maker unacquainted with the sporting ideas of his customer. It is nonsense to lay down a scale of charge, and say, let the shooter stick to it. It were as possible to turn the course of the Thames as to convince some old shooters of the erroneousness of their ideas respecting the propriety of having large charges of shot. The obstinacy with which they continue to use very large sized shot is a proof of this. They will tell you that you talk like a child should you affirm that small shot, with a moderate sized gun, will kill equally as well as large. I can assure thein that I can kill, and
have killed scores of times, the larger sea-gulls with No. 6, when they have gone away with two or three charges of Nos. 1 and 2 fired at them ; and when they have been skinned I have found the large shot in a body of feathers just under the skin as large as a marble, while the small shot had not only cut clean through the feathers, but considerably through the body. I am quite convinced that moor puffings, or any other close feathered sea-bird, can more easily be killed by small shot, say No. 6 or 7, than by larger, if the gun be of sporting dimensions. But to return to the elevation.

It being difficult to determine, on any scale of elevation, while such a diversity of opinion on charges exists, I must endeavour to convince gentlemen of the superiority of my plan, which they will find fully treated on under the head Shooting. However, I think the elevation I have given, will be found to be as near what is requisite as possible, if we continue to load as heretofore; if reduced charges of shot be adopted, a less elevation will suffice. To ascertain what elevation at the breech, for the above scale is requisite, take the thickness of the breech and muzzle, and multiply the difference by as many times as there are lengths of your barrels in the 40 yards, and you will then ascertain what elevation they give of themselves ; and to make up the difference wanted, must be the elevation of the rib, which may be calculated in the same way as the barrels; the length of the barrels being the only way of obtaining a correct idea of the height required. If you should be making Woodcock guns, less elevation is required, the distance of shooting being shorter. In large guns, a greater elevation is required. I believe, however, Colonel Hawker has fallen into an error, when he says that long guns require a greater elevation than short ones. But does not a long gun keep the shot more together ? Is not more force generated ; and is not the initial velocity greater than in a short gun ? If these be facts, why is more elevation required, if the shot do not droop? I apprehend, the Colonel means, if the same height be required to be given above the mark; nothing can be plainer than this—that if one pair of barrels be four inches longer than another, and the elevation the same, there cannot be as many lengths in the 40 yards of the longer barrels as of the shorter; and hence the difference, when multiplied. I think, therefore, he cannot have taken into consideration, the superiority in their shooting; for there cannot be a doubt, that, if a gun keep the shot together longer, it cannot require that allowance for drooping, which a shorter gun does.

There is another objection which I have to make to the present mode of putting barrels together, and then I shall dismiss this part of my subject. I object to making elevated ribs hollow.
Whether they are made hollow for the purpose of saving iron, or of making the barrels lighter, I never could learn, but I hold the practice to be highly injurious to the shooting of the barrels. If lightness be the only advantage, it is a trifling one, as it does not lessen the weight more than three ounces ; and should any water in washing get into the inside through any imperfection in the soldering, it will not fail in a short time, to create such a rust, as will, sooner or later, inevitably destroy the goodness and safety of your barrels. It is on the score of lightness alone, that the practice can be defended. The shooting powers it cannot increase, being more liable to increase the expansion than if they were solid.

I forgot to mention that many internet posts suggest that Krupp made small arms tubes and that was just not the case. From what I can gather 20mm was the smallest tube Krupp made. Bars or blanks were sourced from Krupp and others. Now Krupp may have funded an entity under their umbrella to make tubes of their steel, but this is pure conjecture.

Kind Regards,

Raimey
rse

Chuck, I was reading just the other day in some obscure book on Google that during the American Civil War the barrels being made in Birmingham for their Enfields were begun as 9" steel tubes. They would bore this and then the drilled blank would go to the rolling mill and be extruded to full length. Intersting.....

Joe it is all about both barrels shooting to the same point. Everything else can be fixed with the stock. If, at 40 yards, one barrel shoots two feet higher and two feet lefter of the other barrel that is a major disadvantage, even the way you shoot. And I dont think you can peer down the two barrels and tell me whether they will have the same POI at 40 yards.

And you are grumpy all the time, doesn't have anything to with the weather.

Best,

Mike

Mike, if you want to pursue this subject I sugest you read "Gunfitting: The Quest for Perfection for Shotguns and Rifles" by Michael Yardley, pages 153-155. He indicates moving the barrels to regulate POI is "a final resort" after trying everything else (altering chokes, etc.).

Joe if both barrels shoot to the same point at 40 yards he starts bending the stock or custom stocking to correct shooting too low or too high or canting the gun or whatever.

If they don't shoot to the same point I would sell the gun to someone like you who doesn't care if they shoot to a point and I would take that money and get another one.

Best,

Mike

The post said "regulating barrels" I just took it as talking about double rifle barrels.

Wait a minute...I though you two sporting chaps were single barrel converts....have you tried regulating them yet ?