Rifling Machine

with the 87 grain bullet loaded to its highest permissible velocity and it would probably handle the 60 grain very well. Therefore, in recutting old barrels it is not possible to use the old barrel itself for a rifling guide unless the twist of the old barrel and the required twist for the new cartridge are the same or very nearly so. Two instances of this are the .38-40 being recut to .44-40—the twist in this case is the same, one turn in 36 inches,—and in recutting the .30-30 to .32 Winchester Special. The twist of the .30-30 is one turn in 12 inches while that used for the .32 Special is one turn in 16 inches. Cutting the barrel for the .32 Special with a twist of one turn in 12 inches will not matter much, as the increase in twist in this case will not raise breech pressures to any great extent.

The recutting of the barrels for the above cartridges, using the twist of the original barrel, is mentioned because this requires a minimum of equipment, the original barrel being used as the rifling guide while it is being recut. To do this, the old barrel must have a fair amount of rifling left in it. A lead slug is cast in the barrel, about 4" long, on a rod of steel, as is described in the chaptci on cleaning and lapping barrels, and the oil and emery are used to lap the barrel first, so that it runs even for size, with no very tight or very loose places within it. The barrel is then thoroughly washed out with gasoline and cleaned, after which a new slug of nickel-babbitt, 6" in length, is cast upon a heavy steel rod of a diameter that will just enter the bore easily. Two inches of one end of this rod is turned down to a smaller diameter. In the case of recutting a .30-30 to .32 Special caliber the rod would be turned down to diameter for 2". This section is then filed square and the edges notched at four or five places with a three-square file. This rod is inserted from the breech of the barrel, with a piece of cotton waste or string wound on the rod at the point where the squared portion joins the round portion of the rod. This squared portion is stopped with its end 4" below the muzzle and, with the barrel set muzzle-up, the last 6" of the barrel is warmed with a torch until it is about ready to change color, whereupon the melted babbitt is poured steadily into the muzzle until the bore is filled for the last 6". As soon as the babbitt cools, the cast is pushed a short distance out of the muzzle so that any overflow may be cut off. It is then withdrawn slowly through the barrel, to see that it slides through all right and is not too loose.

The old rifling grooves appear as ridges on the cast and in one of these ridges a slot is cut, the full width of the ridge and 1 to 2" long, following the angle of the ridge exactly and not quite going clear through the cast, leaving about % 0" thickness at the bottom of the slot. A rifling cutter of the hook type is then made to fit this slot very closely and of a depth so that when it is on the bottom of the slot the edge of the cutter just comes flush with the top of the ridge in which it sets. This cutter may be ground to shape from a piece of high-speed steel, such as a lathe cutting bit or it may even be made from a large flat file by heating the file red-hot and burying it in slaked lime to cool, after which it is soft and may be sawed and filed to shape. Leave plenty of chip room in front of the cutting edge by filing or grinding out a space half an inch long and a little over half the depth of the cutter at this point. If the cutter is made from a file, it is heated red-hot after being shaped and is quenched in water to harden, after which the edge is honed with very fine oil stones. If the cuttcr is of high-speed steel, ground to shape, no hardening will he required, merely the honing to give it a smooth, very sharp edge.

A hole is drilled through the bottom of the cutter slot, so that a small punch or nail may be used to push the cutter up out of its slot. The cutter is set in the slot with the hook pointing backwards and the rod is inserted into the barrel from the breech, with the cast carrying the rifling head and cutter going in last. A cross-handle, equipped with a ball-bearing center, has the center drilled and tapped so that the end of the rod opposite the rifling head can be threaded to screw into this ball-bearing center of the cross-handle. Probably the easiest way to make this ball-bearing center cross-handle is to get a ball-bearing bicycle hub or pedal and anneal one end of the shaft by heating to a

A simple design of hook type rifling cutter, using shims to raise the cutter. This is the type which can be made by the individual for use in rerifling old barrels.

red-heat and burying in slaked lime, after which it may be drilled and tapped. If it is not hardened this will not be necessary. Two pieces of hardwood are clamped together and a hole is drilled through them where they meet, just the size of the outer case of the ball-bearing hub or pedal. These two pieces are bolted together at right-angles to the hole drilled through them. A little is planed off the edges of these pieces where they meet each other so that when they are placed around the hub or pedal and the bolts drawn up they will clamp tightly upon it. The ends of these wood pieces can be shaped-up into handles with a draw knife.

After this ball-bearing cross-handle is screwed onto the end of the rod projecting from the muzzle, the rifling head is carefully started into the breech end of the barrel so that the ridges upon it enter the grooves in the barrel. The barrel is clamped tightly in a vise and the rod, carrying the cutter, is drawn steadily and slowly through the barrel and out the muzzle. The barrel is cleaned out and a punch is used to push the cutter out of its slot, and both cutter and slot are thoroughly cleaned. Remove the rod from the handle and put the rod through the barrel from the breech again and attach it to the handle at the muzzle. Start the rifling head into the grooves again, but with the cutter in another groove, and draw the cutter through the barrel a second time. Each time the cutter is passed through the barrel, examine the edge of it and hone it if necessary. After the cutter has passed once through each groove, place a shim of very thin paper beneath it in its slot and, after oiling the barrel with lard-oil, draw the cutter through each groove in turn again, oiling the barrel each time after it has been cleaned out following the passage of the cutter. The cutter may be run through each groove more than once if it will continue to cut without the addition of another shim but be sure and run it through each groove the same number of times. After all the grooves have been recut with one shim under the cutter, the babbitt rifling head will be loose in the barrel and must be melted off the rod, then a new slug of babbitt cast on the rod as before and a slot cut in it for the rilling cutter.

After the grooves have all been cut to within .001" of the proper depth for the new cartridge, the groove-diameter of the barrel will be .002" less than is used for the cartridge in question. The barrel can be measured with a soft lead slug and an outside micrometer or it may be measured directly with an inside micrometer of a size from .2" to 1" as sold by both L. S. Star-rett Co. and Brown & Sharpe, price $14.00.

The bore of the barrel must now be increased for the

Improvise Homemade Rifling Tools

Plate VII

Chambering a rifle barrel by hand.

In uMiig the finishing chambering reamer by hand, the barrel is mounted vertically in the vise, as shown, and both hands exert an equal pressure in turning the reamer wrench. This helps to keep the icamcr running true, cutting equally on all .sides.

new cartridge and for this purpose reamers of left-hand spiral with right-hand cut are used. These reamers are used in sets of three, are equipped with pilots and are drawn through the barrel by a rod attached to the pilot end of the reamer. The first two reamers each remove .005" and the third reamer removes .002". In the case of recutting a .30-30 to .32 Special caliber these three reamers will remove just the right amount, leaving the bore .001" small. Lard-oil is supplied in quantity during this reaming operation, being poured in from the muzzle end of the barrel as the reamers are drawn through from the breech. As you are facing the front end of the barrel reamer turn it to the left, which gives the reamer a right hand rotation as you draw it through the barrel.

After the reaming is completed, the wire-edges or burrs left by the reamers are removed with a stiff bronze brush like the Parker brushes, after which a lead slug is cast on a rod in the barrel and the barrel is lapped with emery and oil until the bore is brought to size.

The regular chambering reamers are used to chamber the barrel for the new cartridge.

In recutting a barrel for a cartridge requiring a different twist, such as recutting a .25-20 Repeater barrel to .32-20, there are the two ways of obtaining the desired twist with a hand rifling bench. One way is to obtain a barrel with the desired twist, in this case one turn in 20", and mounting this on a heavy bench in line with the barrel in which the rifling is to be cut. It does not matter what diameter the bore of this guide barrel is, nor does it matter how many grooves it has. The rifling head is made of steel in this case and has the pull rod on one end as before, and from the rear end of the rifling head a rod extends through the guide-barrel, and upon this rod a length of nickel-babbitt is cast within the guide barrel. This guide barrel is kept well oiled with machine oil and the ball-bearing cross-handle is attached on the end of the pull-rod beyond the muzzle of the barrel being rifled, as before.

The babbitt guide block in the second barrel runs always in the same grooves, and either the guide barrel or the barrel being recut is turned to give the position for each groove being cut.

The second way of rifling the barrel is to have a shaft with a single groove milled upon its surface by a milling machine with a spiral attachment, the groove having the proper twist, in this case one complete turn in 20", to produce the correct twist of rifling. This shaft passes through two blocks, with close fitting smooth bearings, fastened to a heavy bench in line with the clamp blocks holding the barrel being rifled. In one of these blocks holding the shaft with the spiral groove upon it is a pin passing through the block and bearing and entering the groove in the shaft, which it fits closely. Only one pin is used but there as as many holes for it, equally distant from each other around the circumference of the bearing, as you desire grooves in the barrel being rifled.

In connection with this groove business is an argument as to just how many grooves, and whether of an even or odd number, a rifle barrel should have. Winchester and Remington contend that six grooves give the best results, Springfield armory claims they do just as well with four grooves and Savage joins them in this to some extent. The British government says five grooves are the thing, which is the reason our 1917 model adapted from the British Enfield has five grooves. Charles Newton was also an exponent of five grooves, while Eric Johnson turns out eight-groove barrels and other barrel makers make five and seven-groove barrels. This argument has never been settled, as barrels with all these different numbers of grooves have shot well, but the contenders for the odd number of grooves really have what looks like the basis for a good argument, as they say that with an odd number of grooves the part of the rifling head directly under the rifling cutter is supported with the solid steel of the bore, as in odd-number grooved barrels the grooves are not opposite to each other, while in barrels with an even number of grooves the rifling head has a groove beneath the part directly under the cutter and, of course, this groove can give the rifling

Odd versus even number of grooves. Showing how rifling head, directly beneath cutter, is unsupported in rifling an even number of grooves while, in rifling an odd number, the solid portion of the barrel, the lands, support the rifling head by being directly beneath the cuttcr, head no support, therefore the odd-groove fans say this allows the head to spring at this point. So you can now experiment with both to your heart's content and examine the results for your own satisfaction.

In recutting barrels in which the twist of rifling is to be changed, the barrels are first reborcd to their new bore diameter before being rifled. The bore diameter of the .25-20 is .250" while the bore diameter required for the .32-20 is .305". A three or four-groove twist drill with a pilot on it may be used to rough-bore the barrel to a diameter of .292", or a spear-type drill, as was described for drilling out barrels to be relined, may be made of high-speed steel and used to rough-" -bore the barrel. Following the rough-boring, wihich

Barrel Rifling Machine Cutter Head Hook

is done in the lathe, the three spiral-type bore reamers with pilots are used, being drawn through the barrel with the pull rod attached to the pilot end. The first two each remove .005" and the third removes .002" The barrel revolves in the lathe spindle while the pull rod of the reamers is held in a clamp bolted upon the tool-rest slide of the lathe. Plenty of lard-oil is used in these drilling and reaming operations, supplied under pressure by a small pump. The draw rod is really a tube with outlet holes drilled at three points around its circumference just ahead of the reamer pilot. The line from the oil-pump connects to the rear end of the tube back of the clamp on the tool rest of the lathe.

After the bore is reamed it is lapped with a lead slug cast on a rod, to remove tool marks and raise the bore the last .001" to size. Emery of a fine grade in a light oil is used upon the lap.

Now that the barrel is ready to be rifled, it is placed in the two clamps upon the rifling bcnch so that it lines up with the guide barrel or guide bar, whichever is used, in its two clamps or bearings upon the rifling bench. The rifling head is of steel and is a close fit within the bore. It may be made with a simple slot, straight with, not angular to the axis of the rifling head, in which slot the cutter sets and is raised with paper shims as was described for the babbitt rifling head, or it may be the more complicated type with a wedge beneath it to raise it as is described in the description of rifling head types. Whichever type is used the rifling process is the same, the rifling cutter is drawn through the bore, then without changing the setting the index is changed to bring the position of the next groove beneath the cutter and a cut is made in this groove and then in the third groove, etc., until all grooves have been started with the cutter at-the same height setting. The cutter is then raised and the second cut is begun and carried through each groove again, before the setting is changed. This is repeated until all grooves are cut to proper and equal depth. The barrel may be left without lapping the grooves if they are sufficiently smooth, or the grooves may be left .001" to .002" undersize and the lead lap cast upon a rod in the bore used with emery and oil to lap the barrel after the rifling process. The lapping process is usually necessary to remove the wire-edge from the edge of the lands that is left by the rifling cutter, but

Rifled Barrel Liners

Clamp block, mounted in tool rest on compound slide of lathe, to hold oil tubing shanks of barrel drills or rifling heads.

this may be done without deepening the grooves if the finest grade of emery is used. Before doing the lapping, scrub the barrel thoroughly with a Parker bronze bristle brush which will remove most of this wire-edge from the lands. Grooves for the .32-20 are cut .003" deep.

As the rifling cutter comes out of the muzzle each time in rifling a barrel it leaves the muzzle slightly bell-mouthed, so the barrel must be faced off in the lathe to remove this bell-mouth. This may be avoided if the muzzle is faced off smooth and square at first and a piece of steel sweated to it, which is later drilled and reamed to bore size before the barrel is rifled so that it becomes a continuation of the rifle bore. After the barrel is rifled this sweated-on piece is removed which does away with the bell-mouth on the bore.

The .22 rim-fire barrel may be rebored to .25 rim-fire by the reboring process in single-shot rifles such as the Stevens #44:/2 Ideal or the single-shot Winchester. The barrel is rough bored, then reamed and lapped to a bore diameter of .250". The Stevens company cuts the grooves for these .25 rim-fire barrels only .002" to .0025" deep, using six grooves. Winchester barrels were grooved .0025" to .003" deep for the .25 rim-fire. Grooves may be made two and one-half to three times the width of the lands, which is the usual practice for jacketed bullets, or the grooves may be cut very wide and the lands left quite narrow as shown in the illustration of Pope rifling, used for lead bullets.

In changing the .22 rim-fire to the .25 rim-fire, the position of the firing-pin nose must be changed in the breech-block, so that it strikes in the proper place for the larger-headed .25 rim-fire cartridge. The old firing-pin hole in the breech-block is filled up by drilling it out with a drill and tapping it x 32-threads per inch and screwing in a piece of drill-rod threaded 32 threads per inch. Either a new firing-pin is made with the nose in the proper place to strike just within the rim of the .25 rim-fire cartridge, or if the body of the old firing-pin is large enough, the nose is cut off and the body is drilled, a piece of drill-rod is screwed in so that it bottoms in the hole and is then shaped up for the firing-pin nose in the new location.

In marking the location for the hole in the breechblock for the .25 rim-fire pin, the plug is put into the breech-block and the face finished off. It is then as sembled in the rifle and a piece of rod closely fitting the bore and pointed, centrally on the end, is passed down the barrel from the muzzle and a small mark is made on the breech face by tapping the outer end of the rod. This will locate the center of the bore on the breech face, and the distance from this to the proper place to strike the rim of the .25 cartridge may then be measured on the breech face and the hole for the firing-pin nose drilled in the face of the breech-block.

The extractor must be cut out to handle the larger cartridge, and this can be done with the chambering reamer. The extractor is put in place in the barrel either by sweating it into its slot and the barrel re-chambered for the .25 cartridge while it is out of the action or the barrel may be screwed into the action, the extractor put in place on its pin and swung into its slot in the barrel and wedged there with a piece of steel or hardwood extending back to the rear end of the receiver. The barrel is then rechambered while in place in the action.

The recess in the end of the barrel and in the extractor for the cartridge rim can be cut on the lathe, with the extractor sweated in place in its slot in the barrel, while the barrel is out of the action or it may be cut with a face reamer, like an end-mill, with a pilot riding on the lands of the bore, while the barrel is in place in the action with the extractor held in its slot with a wedge.

Head-space in a rifle for rimmed cartridges is the distance from the face of the breech-block, in the closed positions, to the bottom of the recess cut in the end of the/barrel for the cartridge rim. Head-space is important, for if it is excessive so that the cartridge is not heLd forward to its proper place in the chamber upon the moment of firing, the cartridge case backs up until its head contacts the face of the breech-block, which stops it and, as the chamber in the barrel tapers in form, as the cartridge backs up, its walls are not supported by the chamber walls. When this happens, especially if a cartridge case is not exactly the proper anneal, the head blows off from the body of the case, allowing the gas to come back into the action, wrecking it and often injuring the shooter badly.

The required amount of head-space for a rimmed cartridge is easily measured, as the thickness of the rim of the cartridges to be used can be measured with a micrometer in thousandths or ten-thousandths of an inch. As there is some difference in thickncss of cartridge rims between different manufacturers, several different brands should be measured for rim-thickness and as there will also be some variation in rim thickness among cartridges of the same caliber made by the same manufacturer, due to being turned out in different dies, several cartridges of each brand should be measured. The amount of head-space required will be the measurement of the thickest rim found on any of the cartridges, although the variation between the thickest rim and the thinnest one should not be over .005" for best results and not over .008" in the interests of safety.

Head-spacc in a chamber for rimless cartridges (with the exception of the magnum cases, which have a belt raised around the case just ahead of the extractor groove which acts as the rim does in a rimmed case to determine head-space) is the distance from the shoulder slope in the chamber to the face of the breech-block or bolt. As you can readily see, this is an extremely difficult measurement to take. Rifle factories use steel gauges, hardened and ground to the measurement of maximum and minimum cartridges, to test rifle chambers with. These gauges are not available for sale except in caliber .30'06 in which caliber they can be purchased from L. E. Wilson of Wilson Bros., Cashmere, Washington, for S4.50 each. The average gunsmith must rely on new, maximum and minimum car tridges for his gauges in chambering barrels and, in using the chambcring reamer, cuts the chamber until the action will close easily on the minimum case but requires a little force to close it on the maximum case. To pick out these cartridges, a rifle in good condition, preferably new, that turns out fired cases with next to no expansion showing upon them, is the best medium to use. A number of unfired cartridges are run through this rifle to pick the cases desired, being placed in the chamber one at a time, with a piece of steel shim stock laid on the head of the case and the bolt closed upon \t. The maximum case, of course, is the one which will only accept the thinnest shim, or none at all, and allow the action to be closed. The minimum case being the one that will accept the most shim stock upon its head and allow the bolt to close. This steel shim stock can be supplied in ribbon shape at 34f4 per foot by the L. S. Starrett Co., or from automobile parts companies.

In cutting the chambcr it is cut with the roughing reamer and then with the finishing reamer, to a length which you know is less than the required length, while the barrel is out of the action. The barrel is then assembled in the receiver and the finishing reamer run in a little distance, withdrawn, and the chamber thoroughly cleaned. The bolt is then placed in the action, the minimum case placed in the chamber and the bolt is closed upon it. If the bolt encounters any resistance in closing, the chamber is not deep enough so the cartridge and bolt are removed, the chamber is cut a little deeper and tried again. This is continued until the action closes upon the minimum cartridge. Thereafter the maximum cartridge is used as a gauge and the chambering continued until the bolt will close upon it, but requires an effort to close it. The burnishing reamer is then used until the bolt just closes on the maximum case without effort. In case the gauges arc used, the maximum gauge is a "no go" gauge and the bolt must not close upon it but must close with no effort upon the minimum gauge. Head space is important, respect it.

Old rifles with worn-out heavy barrels can be renovated by relining the barrels with other rifle barrels, the original barrel, or a still heavier, old, worthless barrel picked up for the purpose, being used for a jacket. In one case of this kind the model 67 Winchester single-shot barrel was used. The action used was a #44% Stevens Ideal. An old heavy barrel was picked up and was drilled out with a drill having a pilot ground upon it to follow the original bore of the old barrel. A steel Tod was carefully welded to the shank of the drill, using a jig set-up to make sure the rod and the drill were in alignment. The breech end of the old barrel was then drilled out to %" to a depth of about 6,/. The %6" hole in the old barrel was then reamed out to %" and the old threaded end of the heavy barrel was cut off an inch, leaving the %" hole five inches long.

The .22 barrel was then turned down slightly in the lathe so that it would just clear inside the heavy barrel except at the breech and muzzle where the contacts were tight. As the receiver in the model 67 Winchester is a continuation of the barrel, this was cut off and the rear end of the barrel was turned down and threaded to fit the Stevens action, so that it screwed up tightly against the closed breech-block, but not strained against it. The barrel was then loosened one-eighth of a turn and locked in this position by tightening the barrel screw on the under side of the receiver. The outer barrel was slipped over the liner and turned back one-eighth turn (it being an octagonal barrel) from its proper position.. A mark was then put upon the outer barrel with chalk and a chalk mark was put upon the receiver, lining up with the mark on the outer barrel.

The outer barrel was removed and placed in a stand holding it horizontally over gas-jets about 4" apart. This outer barrel was swabbed inside with soldering acid and was placed with its muzzle tight against an asbestos pad and clamped in the stand in that position. The gas-jets were started and when the barrel was hot enough it was tinned inside with solder. A special tool was used for this purpose like those used for tinning the inside of old barrels bored out for the regulation relining tubes. A brass brush will do this tinning job just as well. After the outer barrel was tinned, some more solder was placed within it and the inner .22 barrel, still attached to the action, was started into the outer barrel slowly and allowed to heat up as it was worked in with a twisting motion. This .22 barrel was plugged in each end with asbestos before being started into the outer barrel to prevent solder or flux from entering its bore. When the .22 barrel was all the way in the outer barrel, the chalk marks on the outer barrel and the receiver were lined up and the gas-jets turned out, allowing the barrel to cool.

The recess was cut for the head of the cartridge with a recessing cutter, so that when the barrel was screwed up tightly in the action the breech-block closed on the cartridge closely but without marring it. The groove for the extractor was cut in the rear end of the barrel and the job turned out to be a heavy-barrel target rifle showing good accuracy, while the expense was low. This model 67 Winchester retails for less than $6.00 complete.

This same system may be used where it is desired to retain the old original octagon barrel, by buying a barrel blank, bored and rifled but not chambered, from a barrel-mak^r. This blank can be fitted to the action as this .22 battel was fitted and the old octagon barrel used as a jacket. The blank may be chambered for any cartridge desired that the blank will handle.

After high-power .2$ and .30 caliber barrels are too badly worn or pitted to perform well, they may be recut by the amateur to use a larger jacketed bullet, just as the lead-bullet barrels used to be recut when worn. The .25 calibers may be recut to use a .256 or 6.5 m/m bullet and the .30 calibers can be recut to use a .303 British or an 8 m/m bullet. A .270 Winchester can be recut to use 7 m/m bullet, etc.

As an example we shall recut a .30 caliber, the model '06, to use .303 British bullets of .3125" diameter. The first thing to be done, after removing the barrel from the receiver, is to clean it thoroughly and scour it well with a brass brush. Next we take a piece of round drill-rod and file two inches of its length, at one end, square. We then gash the corners of this square in four places on each corner with a three-square needle file. These gashes need not be very deep, about %2" is sufficient. Just below the square portion we wrap the rod with tow or string so that it is a tight fit in the bore, wrapping it evenly so that it is centered as well as possible in the bore. This rod is inserted into the barrel from the breech and pushed to within 4" of the muzzle. The barrel is set muzzle-up in a vise and heated for 6" back from the muzzle with a torch, but not hot enough to make it change color. Melted nickel-babbitt is poured into the muzzle in a steady stream until the last 6" of the barrel is full, level with the muzzle. When this babbitt cast has cooled, it is pushed forward out of the barrel and the overflow (at the extreme muzzle into the countersunk portion of the barrel muzzle) is trimmed off with a sharp knife. We now have a cast 6" long, 2" of which is upon the rod. We now cut a slot in one of the raised ribs of this cast, which represents a groove in the barrel, V//' long and the full width of the rib plus ;005", .0025" of which extends beyond each side of the rib.- This groove is cut at the same angle on the cast that the rib lies, or in other words, it follows the angle of the rib. This cut starts about 1" from the outer end of the cast and extends toward the rod on which the cast was made. The slot is cut to within J/s" or a trifle less of the opposite side of the cast. A small hole is drilled through the remaining lead in the bottom of the slot, at the center, so that a punch or small nail can be inserted through this hole to push the cutter up and out of the slot.

The cutter to fit in this slot is ground to shape and size from a high-speed steel lathe bit, being ground in length and width so that it can be inserted into the slot without any shake and yet does not bind at any point. A portion in the center is >£" long and is ground with a slope toward one end. The top of this portion is ground with a slope of Sl/i degrees down from the direction in which this portion inclines, forming a hook cutter. This top is ground and honed to a height that brings its cutting edge just level with the top of the rib in which it is sunk in the babbitt casting. In front of this cutting edge a recess long is ground l/s" deep and behind the inclined cutter portion another recess J4" long and }i" deep is ground. These recesses take care of the chips or cuttings. The remaining portions of the cutter body at each end are ground down on the top to .010" below the cutting edge. The cutter portion in the center is carefully ground and honed to the exact width of the barrel grooves, .1767". The cutting edge of the hook is not straight across but is ground to fit the bottom of the barrel grooves which is a slight radius.

A handle of hardwood, 2" thick in the center and a foot long, is drilled through from side to side, at the center, so that the rod on which the cast was made is a close slide-fit in the hole. One side of this hole in the handle is drilled out so that a ball thrust bearing, such as are sold to slip over the shaft of small electric motors with shafts to convert them for vertical use^ i is a close push fit in the hole. The hole in the thrust bearing is bushed to to fit r°d and a washer is placed in the bottom of the hole in the handle before the thrust bearing is placed in the hole.

A %2" hole is drilled through the rod from the end opposite the babbitt cast and a cotter-pin is used in this hole with a washer beneath the pin against the thrust bearing.

The barrel is now fixed in a horizontal position in the bench vise and the end of the rod opposite the babbitt casting is inserted into the barrel from the breech and pushed forward until the end comes out of the muzzle. The handle is now slipped onto the rod, the side with the thrust bearing in it going on last. A washer is slipped over the end of the rod and the cotter-pin is inserted outside the washer.

The barrel is oiled with lard-oil from a pump oil-can, pumped into the bore. The cutter is seated in its slot in the babbitt casting with the cutting edge forward and is oiled with lard-oil and the casting is inserted into the bore with its raised ribs in the grooves. A mark is made at the breech, where the cutter enters, so that we can be sure which groove it enters. The handle of the rod is now grasped in both hands and the cutter is drawn through the bore. As it comes out at the muzzle we must be careful not to bend the casting. The barrel is now cleaned by running a patch through it and the cutter and casting are cleaned, the handle removed from the rod and the rod again inserted through the barrel from the breech, the barrel again oiled in the bore and the cutter oiled. We now insert casting into the rifling with the cutter in the next groove and again mark the end of the barrel at this point, place the handle on the rod and draw the cutter through the second groove. This performance is repeated until the cutter has beeii drawn through each groove in turn. /

We are now ready to start over again at the first groove, but with a shim beneath the cutter to raise it so that it will take a full cut. A very thin paper shim the full width and length of the cutter may be used in the bottom of the slot or a piece of cellophane such as is used for wrapping cigarettes, cough drops, etc. may be used for shim stock. This cellophane is just .001" thick so we will use that. A piece is cut and fitted into the slot and the cutter placed in the slot, the rod inserted through the barrel, the bore and cutter oiled and all marks removed from the breech of the barrel. The cutter cast is now inserted in a groove, the position marked on the breech again, the handle placed upon the rod and the cutter drawn through the barrel. The bore, the cutter and the casting are thoroughly cleaned and the bore and cutter again oiled and started into the barrel again in the same groove and pulled through the barrel. This is repeated in this first groove until the cutter no longer cuts any more, the second groove is then cut in the same manner, and so on, until all grooves have been cut with the shim under the cutter. The same number of cuts are made in each groove. After all the grooves have been cut with one shim under the cutter, the cast will be loose in the bore so we melt the cast off of the rod and, proceeding exactly as we did in making the first cast on the rod inside the barrel, we make a new cast and sink a groove or slot into one of the raised ribs to receive the cutter as we did before. By measuring the cast over the ribs with a micrometer we find out how much we have removed from the grooves. It should be .001", plus or minus an imperceptible amount, from each groove, deepening the groove diameter .002".

Starting with the new cast, we first run the cutter through each groove with no shim beneath it. In cutting the slot for the cutter in this new cast, we

*'ére careful to cut the slot to the proper depth, so that i i the edge of the cutter was the same height as the rib in which the slot was cut. This measurement was made with a micrometer with the cutter in the slot and compared with the micrometer reading of the casting measured over the ribs.

The shim is now placed beneath the cutter in the slot and each groove is again given the same number of cuts, the number being that required to free the cutter in the tightest groove. The barrel should now have a groove-diameter of .312" and to prove this we start an oversize soft-lead bullet through the barrel by gently tapping it into the breech end of the bore with a wood stick and a hammer, after oiling the bore with a thin gun-oil. We push this bullet through the bore with a stiff square-end rod and catch it on loose-piled rags as it falls from the muzzle. We now measure over the raised ribs on this bullet with the micrometer and find that the bore measures .312" in the grooves, as it should.

We must now enlarge the bore diameter between the grooves to a diameter of .303" so we melt the old cast off the rod and make a new cast upon it as before. We now cut a groove or slot in one of the grooves in this casting as these grooves in the casting correspond to the lands in the barrel. We make a new cutter of high-speed steel, ground from a lathe bit, because this cutter has a different contour on the cutting edge from that upon the rifling cutter as the contour of the edge of this cutter will be the arc of a circle with a diameter of .303". Also the width will be less than that of the rifling cutter, the official width of the lands being .0589" in Springfield barrels. The width of the cutter for the lands should be a trifle wider than the lands so that it will be sure to clean up the full width of the land cach.time, so we will make it .070" wide.

The cutter is,ground and honed down until, when it is placed in the slot with no shim beneath it, its

How Rifling Machine Working

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Springfield Model 1959

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Woodworking Tools and Installation Tips

Woodworking Tools and Installation Tips

There are a lot of things that either needs to be repaired, or put together when youre a homeowner. If youre a new homeowner, and have just gotten out of apartment style living, you might want to take this list with you to the hardware store. From remolding jobs to putting together furniture you can use these 5 power tools to get your stuff together. Dont forget too that youll need a few extra tools for other jobs around the house.

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Responses

  • Rowan
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    8 years ago
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    6 years ago
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    6 years ago
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    6 years ago
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    How to repair a 303 worn barrel?
    9 months ago

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