How to Straighten a Gun Rib.—Gun ribs, as received from the manufacturer or dealer, are more or less crooked and winding and must be made straight before being fastened to the gun barrel. Sometimes this straightening can be done with the hands alone, by bending and twisting the rib. If there are short crooks, the hammer must be used. Select a hammer that has a flat pene and this pene must be “across” or at right angles to the handle. See that the pene is not too sharp, but smooth and rounded at its edge. Place the rib to be straightened on a piece of hard wood plank, or what is better, get a piece of two-inch plank about a foot wide and long enough to reach from the floor to a height a little above the work-bench, say about the height of the top of the vise. It may be held in an upright position by means of a screw passing through it into the bench, or it can be so held by setting it on the floor and clamping one side between the jaws of the vise. On this hold the rib, lengthwise with the end of the plank, and using the pene of the hammer, strike blows on the inner or curved side of the rib. Do not strike hard enough to dent or bruise the rib so as to show on the opposite side. By a little practice a rib can be made very straight and true.
How to Fit a Rib.—Sometimes one side of a rib is longer than the other. Fit it into a properly shaped groove in a piece of board, clamp it so as to hold firmly and file away the longer side so as to match the narrow one. The clamps can be made of two pieces of wood placed on each side of the part to be filed, holding them and the rib with wood screws, the rib being moved along as a portion is filed.
How to Fit a Rib to an Octagon Barrel.—To fit a rib to an octagon barrel, file the portion where it comes in contact, square across so as to have all the surface possible to touch the barrel. To fit it to a round barrel, file lengthwise with a half-round file, and so file that the outer edges will fit close, leaving the inner edges a little open, or not quite touching the barrel. A half-round file for fitting ribs to round barrels should have the tang bent toward the flat side so that when the file handle is put on, it will not interfere with filing.
How to Solder on a Rib.—The inner edges of the rib must be filed bright and smooth, so must that portion where it touches the barrel. Bear in mind that solder will not adhere, unless the surface is made bright. This being done wet a short length of the rib with soldering acid, warm it to a proper heat in the forge fire, and with a common soldering copper, also properly heated, tin or cover the melted surface with solder. With the acid wet another distance, say about three inches, heat and tin this, and so repeat until the entire length of the rib has been gone over. Be careful to have plenty of solder adhering to the inner sides. Also be very careful not to heat the rib so as to blue or blacken it, for when so done no solder will adhere, and the surface so made must be brightened up again before going any further with the tinning.
The next thing to be done is to draw-file the gun barrel where the rib is to be fastened on, and care must be taken to have the surface bright and clean, or the solder will not adhere. Place the breech end of the barrel in a clean charcoal fire and carefully warm it sufficiently, wet with the acid, and with the soldering copper tin over where it was draw-filed.
Two tests can be applied to learn if the barrel be sufficiently heated. One is that when a drop of acid is put on it will “sizzle” or boil; the other test is to hold it close to the cheek and if a warm “glow” of heat is felt from it, it is hot enough.
When the surface is tinned, and before the barrel is cold enough so as to harden the solder, wipe off the surplus with a rag, and if the rag be slightly oiled, it will operate all the better. The solder used is common soft solder such as used by tinsmiths. Repeat the process of heating and tinning three or four inches at a time, until the entire length of the barrel has been gone over. Then, after it is cool, place the rib in position, confining it in place with binding wire, putting it round both rib and barrel, twisting the ends pretty firmly together. Fasten the rib in this way, at intervals of about six inches, being careful that the rib is held evenly, closely and firmly to the barrel.
Now commence at the breech, heat both barrel and rib carefully, avoiding all smoke and soot, wetting the joint on each side of the rib with the acid, touching the part with solder taken up on the point of the heated soldering copper. The surplus solder on the inner surface of the rib will flow down to the joint, between the rib and the barrel, as it is heated, and by touching the joint with the copper charged with solder, the outer edges of the joint will be completely filled, and both barrel and rib be perfectly united. So continue until the rib is soldered its entire length. When cool remove the binding wires, and wash thoroughly with warm water. This will remove the acid, which would otherwise rust the bright surface. Wipe dry and if the work is to stand for any length of time, oil it lightly by rubbing it over with a rag that is moistened with oil.
The best way to remove the surplus solder at the joints is by means of scrapers. Take an old flat file, about six inches long, grind the teeth clean off on each side for an inch or two at the end, and also grind the end “square.” By using this tool in the same way that a chisel is used, it is very effective. A scraper made of an old three-square file with the teeth ground away at the end is also a good tool. Carefully remove all traces of solder or it will show after the barrel has been used a little. If the work is to be browned, the browning will not “take” where the solder remains.
How to Re-solder Ribs.—It often happens that double guns are brought in that have the top rib loosened from the barrels at the breech, and sometimes the soldering of the barrels, also at the breech, has been broken, so that they are quite separated. The cause of this is generally an effort to remove the patent breeches by some one who has not the proper appliances for the work. The barrels being caught in a vise, and a monkey-wrench, or some similar kind of wrench, applied, and as the breeches fit very tight, perhaps being rusted somewhat, considerable force is applied, and the torsion or twisting so occasioned starts and separates the parts as described.
To re-unite these parts, remove the breeches, carefully raise the rib as far as can be done without bending it, and hold it thus in place by inserting a slip of wood so as to retain it. Use a slim-pointed scraper and scrape bright and clean the surface of the rib, and both barrels, where the rib comes in contact. Tin the parts with a heavy soldering copper, but do not put them in the fire to heat them; rely solely on the heat of the copper, taking time to do the work. When nicely tinned, put the rib in place, confining it with binding wire, and finish the soldering in the forge fire, the same as when putting on new ribs.
Before putting the rib in place, fill the space between the rib and barrels pretty full of solder, cut in strips, like pieces of wire. If necessary, use the copper to assist the soldering, as they are being worked in the fire.
A scraper for such work may be made of a small three-square file, say about four inches long; grind the sides so as to remove the teeth, and sharpen to a point.
As a precaution against starting the rib from the barrel by heating, put pieces of binding wire tightly around, both above and below, twisting them tightly. With this security there will be no harm done even if the solder be melted between rib and barrel, in proximity to the thimble.
Height of Ribs.—The only way to ascertain the proper height of a gun rib, when put on the barrels, is to take the length of the barrels, and from this length make the calculation, as different lengths require some difference in height of rib. It is to be supposed that forty yards is the distance from the shooter to the object fired at, and at this distance a heavy charge of shot will drop about twelve inches. As the sights on shot guns are fixed, it is necessary that the rib be so elevated as to compensate for this dropping of twelve inches. Of course a lighter charge of shot will not drop so much as the heavy one, but the calculation may be based on the heavy charge.
To ascertain the elevation at the breech, take the thickness of the breech and muzzle and multiply the difference by as many times as the length of the barrels is contained in the forty yards. This gives the elevation of the barrels without the rib, and the difference must be made out by elevating the rib. Many shooters complain that when their barrels have been shortened the shooting is not the same, and they lay this fault to the barrels being cut shorter, when it is often due to the difference of elevation from that they were accustomed to use. Suppose a pair of barrels were to be shortened, say, four inches, at the same elevation there will be more lengths in the forty yards, hence a difference in the sighting and consequently in the shooting.
The calculation for the elevation of ribs is the same as that given for fitting barrels together, and the same principles there given will apply to this subject.