US2379701A - Process of making bullets - Google Patents

Description

July 1945. I J. H. FRIEDMAN 2,379,701 7 I PROCESS OF MAKING BULLETS Filed May 16. 1941 G76 j F'Gf7 INVENTOR. uaH/v H'FR/EDMAN Patented July 3, 1945 PROCESS OF MAKING BULLETS John H. Friedman, Tifiin, Ohio, assignor to The National Machinery Company, Titfin; Ohio, a

corporation of Ohio Application May 16. 1941, Serial No. 393.727

9Claims.

This invention relates to projectiles, and more particularly to a bullet core. and a process of making the same. v s l The principal object of this invention. is to increase the penetrating power of projectiles, particularly small-calibre rifle and machine gun bullets. Bullets of this tylpedesigned to pierce armor plate havebeen made of a steel core encased in a. jacket. The characteristics of the core determine the penetrating ability of the bullet, and the present invention provides a sub-' stantial increase in penetrating ability as compared with other types of. cores and methods of; makingpthe same. Other objects are todecrease the cost of such bulletsand cores, and decrease the. time required for fabricating the same. Other objects and advantages will appear from the following descriptionof the preferred embodiment of the invention. i i In the accompanying drawing:

Figure l is a sectiona l view through a double lolow header showing the completion of the first step in making albullet or. bullet, core according to this invention; A

Figure 2 is a similar. view showing the second Figure 3 is an elevation of a cut off wire or rod blank; I n

Figure 4 is an elevation of the blank formed by the first step;

Figure 5 is anelevation of the blank formed by the second step;

Figure 6 is an elevation of a completed bullet or bullet core cut longitudinally and etched and showing theflow lines of the metal;

Figure 7 is across section through a completed jacketed bullet. 1 l I have illustrated suitable punches and a die for carrying out my novel method in a conven tional double blow soliddie cold. header of the type commonly used for making bolts and similar.

headed articles. Such machines include a frame carrying a fixed solid die; a reciprocating slide carrying two punches, each of which is alined with the die on alternate strokes of the slide;

means for cutting off blanks from wire or rod stock and carrying a fresh blank into alinement with the die beforeeach operating stroke of the first punch; and means for ejectingthe'lolank from the die after each. operating stroke of the second punch. A high speed machine of this type which ma :be used to carry out thelpresent process is illustrated in the patent to Clause, No. 1,932,396. A suitable lolank cut-off and carryover mechanism is shown in th patent to Clouse o. 1,856,023,. and asuitable knockout in the patent to Clouse No. 1,968,128. Itwill be understood, however, that any desired type of machine I may be, employed. H

Thedie it; shown in Figures; 1 and 2. is mounted in the frame of a header andis arranged to receive cylindrical blanks l I (Figure 3 which are carried into alinement with the die by the cut-off mecl'ianism of the machine. A knock-out rod I2 isslidably mountedin thedie its forward end i forming thebottom of the die during the worka conical portion M tapering down to a diameter ing of the blank. The die is formed with a cylindrical portion l3 adjacent its forward face which is of greater diameter than lthestock ll, and, when the bullet is to be formed with a boat-tail,

less than the stock diameter.

The header slide, which is reciprocable toward and away fromthe die llhcarries a movable pororder toinsure accuracy. In the normaljoperati onof the machine, the punch I6 alined with the die aiter a fresh blank has 'been cut off and positioned in iront of the die, and the header slide on its forward stroke then pushesthe .flolank into! f the dieand carries out the first operation, the

parts at the end of this. strokeloeing arranged as shown in Figure 1. For the next forward stroke the punch H is alined. with the die, the lolank re-" maining in the die, and at the completion of this i be provided with a suitable knockout mechanism. l

stroke the parts are arranged in the position shown in Figure}.

provided with a cylindrical opening 18 of Sufi)- stantially the same diameter as the stock and a conical portion. 19 communicating therewith and is suhstantiallythe same diameter as the opening it in the die Hi, and which isiormed with an ogival or other shapeflwhichit isdesired to impart to. the front end of the bullet; or bullet core.

In order to insure the blank remaining in the die andnot sticking to the walls of the opening in the punch either. or both of the punches may As illustratedthe punch I6 is provided with an axial bore. communicating with the end of the conical opening 1 l9 and slidably supporting. a knockout rod 2 I. At its rear end the rod 2 lis provided 'witha head 22 thrusting againstla com-,

In the embodiment illustratedthe' punch I6 is seated upon an abutment portion 24 which is solidly mounted upon the punch carrier 15. A sleeve 25 is illustrated surrounding the spring 23 and the head 22 and abutting against the rear end of the punch l6 and the forward face of the solid abutment 24. The punches are fixed in the punch carrier by bolts or any other suitable fastening means (not shown) and with the arrange- .ment illustrated the knockout rod 2| is free to be pressed rearwardly when it is engaged by the end of the blank at the Completion of the first stroke of the header as illustrated in Figure 1. When the header slide recedes from the position illustrated in Figure 1 the tension of the spring 23 frees the blank from the 'walls of the punch so that the blank remains in the die for thenext operation.

My novel process in its preferred form is illustrated by Figures 3 to 6 showing the successive stages of the blanks. The blank I I as cut off from wire or rod stock has "a diameter a and a length substantially greater than the length of the completed bullet. In the first blow the end the metal, somewhat similar to the surface effect of wire drawing, except that the metal isworked throughout and improved physical properties are imparted to it. I use theterm upsetting to. designate the type of forging in which the metal is expanded in diameter and decreased in length by endwise pressure. The extreme end of this portion 26 has a diameter b smaller than the stock diameter; The remainder of the portion of the blank which enters the die is upset into.

a substantially cylindrical portion 21 merging into the larger end of the conical portion 26 and having a diameter c greater than the stock diameter. The opposite end of the blank enters the conical portion It in the punch l6 and is extruded into a conical end 28. The remainder of the blank fits within the cylindrical portion l8 of the punch l6 and is retained as a cylindrical'portion 29 having substantially the diameter aof the original stock. It will be understood that on this first blow the cylindrical portion 21 of the blank may not be completely filled out into the cylindrical portion I3 of the die 10, since it is only necessary to impose sufiicient pressure on the blank to upset and extrude the conical end 26 and 'extrude the conical end 28. Thus to make certain that the blank remains in the die when the header slide retracts after the first blow, the punch I6 may be provided with the knockout rod 2| as described above.

On the second blow the conical portion 28 at the front end of the blank is further extruded to reduce the extreme end 3| to a relatively small diameter. *1 permit this extreme end 3| to extrude into a small diameter cylindrical bore in the punch in the preferred embodiment, as illustrated in Figures 2 and 5, in order to limit the pressure on thetools and provide an escape for any excess volume of metal in the blank without throwing an excessive flash at the face of the die Ill. The cylindrical portion 29 is upset into the cavity in the punch I! so that the portions 28 and 29, by the combined extruding and finished bullet.

carried out by cold working or working below the temperature of rapid grain growth or re-.

upsetting action, are brought to a substantially ogival shape indicated at 30 in Figure 5. The cylindrical portion 21 and the conical end 26 remain substantially unchanged except that they may be more completely filled out into full sharp contact with the walls of the die by the increased pressure of the second blow. After the second operation the header slide again recedes and the finished blank, as -illustrated in Figure 5, is-

ejected from the die II] by the knockout rod I2.

- Any flash that may be formed at the junction of the cylindrical portion 21 and the ogival nose 30 at the face of the die may be knocked off in any convenient manner. The extreme end 3| of the blank may then be formed into apoint 32 in any suitable manner, as by a turning operation. The finished blank 33 may then be used as a bullet, or, in accordance with the usual practice, may lbe enclosed in a jacket 34 to form the The operations are preferably strength in the direction of the flow lines and the shear resistance in a direction transverse to the flow lines. Ordinary rolled rod or drawn wire stock embodies flow lines produced by the hot rolling of the material which extend axially of the stock and substantially parallel to each other. Thus when such stock is cut to form an ogival or pointed end the'flanks of the point or ogive intersect or cut across the-flow lines, leav ing'the ends exposed. When such a pointed end attempts to pierce or penetrate metal the 'decreased shear strength along the direction of the flow lines is opposed to the shearing and abrasive action of the metal being penetrated, resulting in a breaking up and failure of the 'metal of the projectile and dissipation of its ener y.

Bullets fabricated in accordance with the present process, however, have the fiow lines substantially conforming to the contour of the bullet, as illustrated in Figure 6. Theextrusion of the end of the stock deeply and thoroughly works the metal by bunching the fiow lines and drawing them toward a point. The upsetting of the stock in the cylindrical portion 29 similarly works the metal thoroughly and spreads the flow lines outwardly to the maximum diameter a. A similar effect is produced on the conical portion 26 or boat-tail of the bullet. Thus-the bullet produced in accordance with the present invention has the maximum strength which can be developed in the'metal opposed to the abrasive and shearing forces acting upon the ogive when the bullet penetratesarmor or other solid material,

so that the bullet penetrates through'asubstantially greater depth of armor plate or the like before the energy of the'bulletis dissipated or the metal of the bullet fails.

While the extreme p oint 32 of theogive may be formed by cutting a point in'th'e extruded end 3| of the blank, no substantial'l'oss of penetrating l in armpr piercing artillery projectiles.

ability is effected' because the diameter tr the extrudedend -iil isbut a small fraction of the total diameter and the metal is confined by the surrounding extruded and upset metali In addition the end 3l receives the greatest amount of working and thus has maximum hardness-and strength.

Preferably-the conical end 28 formed onwthe blank by extrusion in the first punch 16 isof such angle and length as to insure thorough. working, of themetal throughout the ogive by the second blow, so as to develop the improved metal properties resulting from the cold forging throughout this portion of the bullet. 'In the.

illustratedembodiment the taper of the conical portion 28 is less than the taper of the ogival cavity 20 in the portion of that cavity having a diameter equal to, andless than, the diameter of the small end of the portion 28. Thus the punch l1 first contacts theextreme end of the blank and applies the upsetting force to the entire blank. As the punch l1 advances toward the die,.all of the metal of the'conical portion 28 and of the cylindrical portion 29 starts to upset. As the resistance to upsetting increases, the forward end of the conical portion 28 begins to crawl down 'into the smaller portion of the cavity 2|], ultimately extruding into the cylindrical end 3|. Thus the major portion of the flank of. the ogive is formed by metal which is both extruded and upset, and the portion of smaller diameter than the diameter of the end of the conical portion 28 is first extruded in the punch l6, then upset, and finally extruded in the punch I1. I l

The same efiects are obtained when the bullet is encased in a jacket 3.4. The jacket may be drawn from a corrosion resistant material which diameter than the diameter of thestockforging serves as a lubricant and aids in starting the bullet into armor plate and the like as is customary When the bullet strikes the jacket promptly disintegrates and the penetration is effected by the core.

, It will be understoodthat the bullets or bullet cores may be manufactured in accordance with this process from any suitable material. Ordinary medium carbon steel has been found to be satisfactory from'the standpointof density and toughnessand isalso readily worked in the cold forming operations of myinvention. terials having special properties to meet particular conditions may, however, be used. 3

Although a preferred embodiment of my invention has been described in considerable detail it will be understood that many variations and modifications may be resorted to without departing from the scope of the invention as defined in the following claims.

I claim:

1. The process of making a bullet from a cylindrical blank or wire or rod stock comprising in one operation forging an end of the blank to reduce its diameter, upsetting another portion of the blank to increase its diameter, and main-- dricalportion of larger diameter than the diamnose merging with said body and tapering to a 1 diameter smaller than the stock. diameter.

eter-of the stock, and upsetting and. forgingsaid intermediate portion and the adjacent enema tion ofthe blank to form a pointed endmerging into said substantially cylindrical portion. 3. The process of making a bullet from a blank of substantially cylindrical'stock comprising confiningan intermediate portionot the magni er the blankto maintain the sameat substantially its original diameter upsetting, a portion of the blank on one side of said intermediate portionto form a substantially cylindrical portiongofi larger the end portion of the blank on the; otherzside of said 1 intermediate portion :to fornr a lconical' portion,;and; further forging and upsetting the said intermediate portion and the said conical portion of the blank to form a pointed end merging into said substantially cylindrical portion.

4. The processof making a bullet from ablank A of substantially cylindrical stock comprising up- 1 setting a portion of the blank to form a substantially cylindrical portion of larger diameter than the diameter of the stock, forgingan end ofthe blank to form a conical portion spaced from said substantially cylindrical portion by an intermediate length of substantially the original diameter of the blank, and upsettingthe for ed end and intermediate lengthto forma pointed end merging. into said substantially cylindrical por-.

tion. 7 l l H 5. The process of making a bullet from a blank of substantially cylindrical stock by cold. working, comprising upsetting a portion of the blank into a cylindrical body of larger diameter than the stock, forging an end of the blank to form a conical portion while maintaining the length of the :blank between saidbody and said conical portion at substantially the original,

diameter of the blank, and upsetting said conical portion and said length of the blank to forma 6. The process of making a bullet from a, blank of substantially cylindrical stock comprising enclosing an intermediate portion of the length 1 of the blank in a cylindrical die opening of substantially the same diameter as the blank so as to maintain, said intermediate, portion atsub- Other mastantially its original diameter, upsetting one end of the blank beyond said intermediate portion intoa die opening to form a substantially cylindrical upset portion of greater diameter 1 than the original diameter of the blank and in another operation upsettingthe opposite end of theblank and said intermediate portion into a pointed end merging with said upsetportion.

, ,7. The process of making a bullet from a blank of substantially cylindrical stock comprisingenclosing an intermediate portion of theglength of the blank in a cylindrical die opening of substantially the same diameter as the blank so as to maintain said intermediate portion at substantially, its original diameter, upsetting one end of the blank beyond said intermediate portion into adieopening to form a substantially cylindrical upset portion of greater diameter H than the original diameter of thenblank and,

while said cylindrical upset portion is retained in its die opening, upsetting the opposite end of the blank and said intermediate portion into i a pointed end merging with said cylindrical upset portion. l l

8. The process of making a bullet'from a blank of substantially cylindrical stockcomprising: enclosing an intermediate portion of the length of ,the blanktin aicylindricaldie o'peningjof substantially the samediameter as the blank so as to maintain, said intermediate :portion at substantially its original diameter, upsetting one:

end of the blank beyond saidintermediateportion, into a die opening to form a-siibstantially than the original diameter of the blank and, while said cylindrical upset. portion is retained in its die opening, upsetting'and'extruding the opposite end ofthe blank and 'said intermediate portion ,intoa pointed end merging with said upset portion.

9. The process of making a bulletfrorn-ablank of substantially cylindrical stock comprising cylindrical upset portion of greater diameter enclosing an intermediate portion offlthe length-J ofthe blank in a cylindrical die opening of-- substantially the same diameter as the blank-s01 as to maintain said intermediate portion ;at

portion into a pointed upset portion. a

: JOIifNl-It FRIEDMAN z

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