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Original barrel rifling method???

taperloctaperloc Member Posts: 420 ✭✭✭
edited August 2008 in Ask the Experts
Many years ago, I read an article about how rifling was first produced in a rifle barrel. The article stated that the original method of producing the desired twist was to cut the groves straight down the barrel and then heating the barrel to the point where it could be clamped and the barrel turned to obtain the twist. After this process, flats were milled on the barrel suffices to stress relive it. This lead to the idea that an octagon barrels was better than a plain barrel.

Is there any validity to this story?

Comments

  • PelicanPelican Member Posts: 1,061 ✭✭✭✭
    edited November -1
    I don't believe this would guarantee a constant twist due to variations in temperature along the length of the barrel.

    JMHO, Pel
  • 11b6r11b6r Member Posts: 16,725
    edited November -1
    That's a new one on me. Method I have seen- a wooden rod with a spiral groove cut into the rod fits thru a block with a pin the rides the groove- so as rod is slid in and out thru the block, it turns. On the tip of the rod is a hardened steel tooth that is hinged to the rod. The tooth is raised out from the rod by shimming it with paper. Lard was used as the lubricant for the cutting tooth. A shallow groove would be cut, the barrel rotated, another groove cut, etc. after all grooves had been cut once, a bit of paper would be slipepd under tooth, raising it by that thickness, process repeated. Oh- how did you get the spiral on the wood rod? Wrap a cord around the rod, mark it, shape you groove with a really sharp pocket knife.
  • Bert H.Bert H. Member, Moderator Posts: 11,274 ******
    edited November -1
    quote:Originally posted by taperloc
    Many years ago, I read an article about how rifling was first produced in a rifle barrel. The article stated that the original method of producing the desired twist was to cut the groves straight down the barrel and then heating the barrel to the point where it could be clamped and the barrel turned to obtain the twist. After this process, flats were milled on the barrel suffices to stress relive it. This lead to the idea that an octagon barrels was better than a plain barrel.

    Is there any validity to this story?



    John,

    Very doubtful story. Once you get steel hot enough to be ductile, it will not deform (twist) with any uniformity. Typically, once it begins to turn or twist (at the weakest point), it will continue to twist at that spot only, as it is now much weaker than the remaining length.

    To the best of my limited knowledge, early rifling was hammer forged versus being cut.
  • glabrayglabray Member Posts: 679 ✭✭✭✭
    edited November -1
    Whether it was used to put a twist in rifling or not, it was not at all uncommon for old-time blacksmiths and wrought iron workers to put a uniform twist in iron or steel. My Dad did it a lot. You need a good forge pot and a uniform fire built up using smithing coke, not coal. They would heat the metal piece to a uniform color which indicated a uniform temperature. The color they looked for varied from a cherry red to almost yellow depending on the metal and the amount of twist to be put in it. It is very easy to twist the hot metal and as long as the piece is of a uniform cross section and the color is uniform the twist comes out uniform also. I've seen it done many times and done it a few myself.
  • nononsensenononsense Member, Moderator Posts: 10,642 ******
    edited November -1
    taperloc,

    Without meaning any disrespect to those who have tried to research rifling techniques, I have a paper in my archives written decades ago which is lengthy but accurate for 'general rifling technique'.

    The first paragraph is an annotation from another paper that I use for research. The photograph at the end of the article is from a current shop that produces period rifles.

    History of Rifling

    The muzzle loading rifled bore goes back to 1498 when Gaspard Zollner used straight rifling in a hand gun to overcome fouling caused by poor powder. A couple of years later Augustus Kutter used helical rifling and a gun having six grooves with a helix of one in twenty six was made in Hungary in 1547. This gun used to be in the Rotunda years ago, but has long disappeared. R.M.L.s (Rifled Muzzle Loader) were still in use in the earlier part of the last (20th.) century. The early breech loading rifled guns (R.B.L.) were so unreliable that a return was made to R.M.L.s for some years. The Russians used "shunt" rifling having a double groove, a deep groove allowing the studs to slide freely during loading and a groove decreasing towards the muzzle, with which the studs engaged to provide rotation on firing. There is a paper on 'The History of Rifling' in Vol. 12 of the Journal of the Ordnance Society. The official title of the device shown pages 50 & 51 is 'Apparatus Lifting Guns, Hurst Pattern, Mk.I L for R.M.L. 38 Tons'.

    The next step was the rifling, the most important process of all. Although apparently complicated, it is in reality simple. First, a "rifling guide" is prepared. Ordinarily this is made from a round stick of timber two to three inches in diameter and some four and a half feet long. This is carefully turned to the requisite size in a lathe and then the circumference is divided accurately into five or seven equal parts3. A withe of pliant oak about one-quarter inch wide and some six feet long is then prepared. One end of the withe is fastened to the center of one end of the guide with a nail in such manner that it rotates freely.

    Starting at one of the seven divisions, the withe is wrapped carefully around the wooden cylinder so that it makes exactly one symmetrical turn in the entire length. that is to say, one turn in approximately 48 inches.

    4 Dressing out with a dressing stick

    A pencil mark is then made along the side of the withe and this process is repeated for each one of the remaining divisions. When this step is complete there will be seven spiral marks (or five), equally spaced and symmetrical around the wooden cylinder and these indicate the twist or speed of the rifling. With each one of these seven symmetrical spiral marks successively as a guide, a second spiral line about a quarter of an inch away is drawn exactly parallel to each of the seven original sets of spiral markings. The wood between each of these seven paired parallel lines is removed carefully to a depth of perhaps a half-inch, leaving as the final stage in the preparation of the guide a wooden cylinder having a set of seven symmetrical spiral bands each turning once in about 48 inches. At this stage the cylinder looks much like a long wooden threaded bolt. If the spiral or twist of the rifles were much sharper than one turn in 48 inches, the weapon would be ineffective. The bullet, as the mountain men say, "would strip its patch" at the higher speed of rotation. Consequently the majority of the rifles in the Great Smoky Mountains have a spin or twist of approximately one turn in 48 inches.

    5 After the rifling guide is made as described, a "head block" is prepared. It is a piece of hard wood about an inch thick and five or six inches wide, having cut in it a hole which is the exact reverse of a cross-section of the rifling guide with its spiral bands. In other words, the head block bears the same relation to the rifle guide as a nut does to a bolt. Ordinarily the bearing surfaces in the head block were lined with leather which, when well greased, allow the ridges of the rifle guide to slip through with ease.

    The rifling guide and head block are mounted on a stout timber long enough to hold both the barrel of the rifle and the full length of the rifle guide in one straight line. This timber is anchored firmly so that it is immovable, and the block is fastened permanently to it near one end in such manner that when the rifle guide is threaded through it, the latter can be moved back and forth its full length without undue vibration, imparting meanwhile the proper rotation to the rifling tool. The barrel is mounted in the exact axis of the guide, so aligned that the rifling tool, which will be described, will pass through the barrel in response to a back and forth motion of the rifling guide. A twist corresponding to the twist of the guide is imparted to the rifling tool, which in turn cuts the grooves or rifles in the barrel.

    The rifling tool consists of a steel rod somewhat more than four feet in length and of a diameter a little less than the bore of the rifle. One end of this rod is fastened firmly to a chuck or slot in the end of the guide so that it will turn coincidentally with the guide. The other end, for a distance of some four inches, has cast upon it a lead block of exactly the bore of the rifle. This is dome by winding a string about the end of the rifling rod to form a narrow band equal to the bore of the rifle. Then the rifling rod is inserted into the end of the rifling barrel for a distance of some four inches. Melted lead is poured around the rifling rod. The lead is kept from running down the barrel by the string barrier. When the lead is hard the rod is removed from the rifle. It will be seen that there is molded on the end of the rifling rod a lead plug of exactly barrel diameter.

    The next step is to seat the "saw" in the lead plug. The saw is pictured most easily perhaps by visualizing a small section of a hack saw blade having some six or eight teeth. This saw is inserted in the lead plug in such manner that the teeth project slightly from the side, giving them only a limited clearance or cutting surface. It is necessary to have the long axis of the saw align precisely with the line of twist of the rifling. This is done by first threading the rifle guide into the head block; than the rifling rod is fastened by the clamp to the rifle guide and the other end of the rifling rod with its lead plug is pushed through the barrel of the rifle until about two inches project on the far side. Then, by means of a steel tool, whose width is exactly that of the width of the "saw", a longitudinal groove is cut in the lead plug. This is done by moving the lead plug back and forth by alternately pushing and pulling on the guide for the proper length, and deep enough so that the saw will be inset far enough to give rigidity. Ordinarily this depth is about one-sixteenth to one-eighth of an inch.

    After the saw is put into its groove, with the teeth projecting but little, it is ready for use. The rifling guide is threaded through the head block, one end of the rifling rod is inserted in the end of the guide, and the other end carrying the lead plug and its saw, well lubricated with unsalted tallow, is inserted in the barrel. Drawing the rifling guide back and forth through the head block imparts the proper spin to the saw for the entire length of the barrel, and a spiral groove is cut, turning one in about 48 inches.
    When the saw has cut the groove as deeply as it can, the guide is withdrawn from the head block and inserted again, one groove to the right, and the process repeated until all seven parallel grooves successively have been cut out. Then the saw is removed from the plug and raised up by putting a strip of paper at the bottom of the groove under the saw. Then the entire process is repeated. Eventually, when the rifles are cut "ten to fourteen papers deep," there results a barrel having on its inside seven spiral grooves, the counterpart of the rifling guide in so far as twist is concerned, and deep enough to transmit a spin to the bullet when the rifle is fired.

    Making the rifle stock

    The newly rifled barrel has to be "dressed out" to smooth the rifles or grooves, and the ridges between these grooves, called the "lands". To perform this operation a "dressing stick" must be prepared. This is made upon a hickory rod somewhat less in diameter than the bore of the rifle. On one end of the hickory rod a lead plug is run in precisely the same manner as the original lead plug above described was run on the end of the rifling rod, the difference being, however, that this time the lead plug on the end of the dressing stick has the pattern of the rifles on it.

    A saw corresponding to the original saw is inserted in the lead plug in exact alignment with one of the rifles and midway between the ends, and a second saw, the width of the lands, and in exact alignment with one of the lands, is inserted also. This dressing stick, well greased, is drawn back and forth through the barrel until the rifles and lands are smooth and evenly cut. Usually from a day to a day and a half was required to rifle and dress out a barrel in this manner.

    Strictly speaking, these rifles had no caliber in the ordinary sense of the word. Usually, however, four kinds of rifles were made: one of about .35 caliber (0.35) inch, which was called a squirrel gun; one about .40 caliber, called a turkey rifle; one about .45 caliber, called a deer rifle; and one of approximately .50 caliber called a bear gun.

    After firing from 80 to 150 rounds it was often necessary to redress a rifle, that is, to resharpen the edges of the rifles and clean the lands. The redressing was done in the manner indicated above by means of a dressing stick provided with both rifle and land saws; and naturally the bore became a little larger. It was usually necessary also to cut off an inch and a half or thereabout from the breech of a rifle that had been fired this number of rounds because at the point where the powder actually burns, the iron gradually becomes eroded and an enlarged chamber forms which eventually would cause the bullet to shed its patch. The shooting age of a mountain rifle can be guessed approximately, therefore, by the length of the barrel.

    To finish the barrel after the rifling is complete, several more steps are necessary. A thread has to be cut in the breech and in this is screwed the iron breech block which closes the rear of the barrel. Usually the breech block is made with a tang from two to four or five inches long. One or two holes, drilled in the tang, provide entrance for screws which fasten the barrel securely to the stock. Next, if the rifle was a flint lock, a touchhole had to be bored in the side of the barrel about one-sixteenth of an inch in front of the breech block. If the rifle was one of the percussion type, a hole was drilled and threaded barely in front of the breech block in which was fitted the side tube carrying the nipple for the percussion cap. Along the barrel two or three metal tabs were brazed lengthwise through which holes were made. Metal pins were driven through these to fasten the barrel securely to the stock. The addition of front and rear sights completed the barrel.

    riflingmanualre5.jpg

    Best.
  • rhmc24rhmc24 Member Posts: 1,984 ✭✭✭✭✭
    edited November -1
    A few comments from someone who has been there & done that. It is not generally known that in the early days of firearms a round barrel was a luxury. Forging of barrels ordinarily produced one with flat sides, usually octagon. I have owned and worked on clients wheellock pistols with apparently round barrels (the outer half or so) but below in the stock the unfinished side of the barrel was the lower half of an octagon. Obviously the exposed top of the barrel had been rounded for whatever reason, probably appearance. I have never seen a barrel with its pin loops brazed on. Except for an occasional repair, usually soldered not brazed, there are two common methods. One is a dovetail similar to now seen on front sights of .22 rifles. The other, less common, is something of a staple, in which holes about 3/8 inch apart receive the "staple", the ends of which are peened in around the hole to secure it. I have worked on scores of guns from the 1500s thru the 1800s.

    A friend of mine built a rifling rig similar to that described by "11b6r" above. That design using one spiral track is a lot more practical to make and equally effective than one with a separate track for each land/groove. Seven tracks is really doing it the hard way. In use, the single track works through a guide, collar assembly or "head block", also of wood, in which there are slots (7 in this case) through which the ram reciprocates, moved from one to another as the job proceeds. There are several design variations possible on the 'head block' theme.

    I think a decimal may have been dropped in the reference to redressing a barrel. It is true about the muzzle receiving soonest wear but certainly not so soon as 80 or so rounds. Possibly it would be known on bench rest rifles but that is a reason why they were fitted with false muzzles. My grandfather grew up (1870s) shooting his grandfathers kentucky rifle firing hundreds of times and never had any such maintenance done. He was a stickler for accuracy and would have known if he had a problem. On the other hand I have seen several plains rifles in which the muzzle wear was apparent. Muzzle wear is common on all muzzle loading guns, probably from many, many loadings. What it took to produce significant wear I won't guess but I have measured it many times in muskets and other smoothbores.
  • mcasomcaso Member Posts: 1,120 ✭✭✭✭✭
    edited November -1
    Many years ago, I read an article on the four types of rifling. It said that one was to take the barrel and twist it, which resulted in a tube that squezzed the ball around as it traveled down the barrel thus exiting with a spin. Don't ask, I don't know. The article showed what the four typs looked like. If I could draw pictures here I would.
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