US1783261A - Process and apparatus for making bullets - Google Patents

Description

DEC. 2, 1930. ROUSSEAU 1,783,261

PROCESS AND APPARATUS FOR MAKING BULLETS Filed Sept. 5 192 Era/v1.5 A As R0056 an a 'core has been placed in the jacket. operation 1s ordinarlly CflIIlGCl" out in a suit- Patent ed Dec. 2, 1930 YUNIVTVOEDYSTATESA PATENT OFFICE STANISLAS ROUSSEAU, OF ALTON, ILLINOIS,:ASSIGNOR TO WESTERN. CARTRIDGE COM: PANY-,. OF EAST ALTON, ILLINOIS, A CORPORATION OF DELAWARE rnoonss'inlvn APPARATUS FORM KING BULLETS 1 Application filed September This inventionpertains a process and apparatus for making bullets, and more par-. ticularly .for making bullets of the jacketed type usually used in high powered rifles.

5 In the manufacture of this type of bullet a heavy core, usually of lead, is placed within a jacket of harder metal, such as copper or steel. After the core'hasbeen placed within "the jacket, the former is usually condensed 10 by pressure so as torender the material as dense as possible and to insure that it will fill the jacket completely.

In some types of bullets the rear end thereof is formed with a taper so as to improve. its

ballistic characteristics. This form of bullet is known as the boat tail bullet and used. in many high powered rifies. Inorder to give the proper form to the tail of a boat tail'bullet, thesame is usually re formed afterthe Such an able die having a punch adapted to co-operate therewith to carryout the forming opera- "tion. Such an operation usually is carried out while both the core and the jacket are under pressure. Accordingly not only must heavy pressures be sustained by the punches and dies involved in the manufacture of these bullets, but when pressure is applied to the rear of the j acket", there'is a tendency of the jacket buckling at the junction of the tapered and cylindrical portions.

One of the objects of this invention, therefore, is to provide means by which the operationson such bullets may be carried out so as to obviate the objections noted above. Another object is to provide means whereby the operation on the jacket may be carried out while the core metal'is unconfined.

3 Further objects will appear from thefollowing description, takenin connection with i the accompanying drawing, in which Figure l] is a view partly nsect on of a 5 bullet of the typeinvolved in this invention with its core inserted therein, but before he -ing finallyformed; F r Figures 2 to Ginclusive are sectional vlews, somewhat diagrammatic 1nform,.1llustrat1ng the successive steps of the method embodying s, 1926. Serial NO. 13.33%.

this invention and representing cross-sectional views of'the punch and die; and j 1 Figure Tie; a side view of the finished bulet. Referring to the accompanying drawin the bullet consists-of a core 1 of lead or similar material enclosed in a jacket 2 of copper, steel orlother suitable metal. In theordinary process of manufacture, the jacket 2 is formed and the core 1 is theninserted therein, as shown in Figure 1; j a i j The process of re-forming the tail of the bullet in accordance with this invention then begins. 7 As shown in Figure 2, the bullet is placed ina die 3 having aflared 'opening t adapted to provide a guide for a correspondingly tapered tip '5 of a forming'punch 6. The end of the punch6 is provided with a tapered cavity 7 adaptedto engage thetail of the bullet and whose taper is such as to reform the jacket to a corresponding taper when the punch is forced home in thedi'e." During.

further formed to a conical form having a taperofabout 9.. In this casealso,'the guide 4 of. the die operatesto center the tip 5 of a punch 9. During this operation, as well as that represented incFigure 2, the core metal 1 is unconfined and may flow freely under the pressure applied to the jacket during the re -forming operation. It will beunderstood, therefore,that only a moderate pressureais necessary on the punches 6 and 9 and that only a moderate pressure is placed upo-n'the die 3 during these operations. Accordingly there "is little danger of breaking the; dies or the punches,- or of buckling the jacket.

After the tail of the bullet has been roughly formed, as described for Figures 2 and 3, the entire bullet, jacket and core together, are compressed endwise so as to shorten and condense the bullet and its core. This operation is represented in Figure 4, in which a punch 10 is brought down against the outside of the tail of the bullet with the bottom of the recess engaging it and is so dimensioned as to compress the entire bullet endwise. The core metal 1 is still unconfined in this operation so that it may flow outwardtoward the open end of the jacket. Accordingly much reduced strain is put upon the punch and die and the tendency of buckling is again obviated.

Figure 5 represents the next operation in which the core metal is compressed and condensed. In this case a guide 11, similar in shape to the punch 9 of Figure 3, is inserted in the die with its centering tip 5 engaging the guide 4 so as to support the jacket exteriorly, while a punch or ram 12 is brought down upon the core metal 1 so as to compress and condense the same, While the jacket is supported. This support of the jacket is, however, such that it is not contracted during this operation, for the guide 11 takes against the jacket at about the end of the stroke of the punch 12. This operation renders the core more dense and forces the metal thereof into close contact with the jacket throughout, while the acket is not really positively constrained.

Figure 6 represents the final forming operation for the tail of the bullet. In this case a sizing punch 13, having its interior cavity 14: formed accurately to the finished taper of the tail of the bullet, is brought down upon the tail of the bullet, being guided by the centering elements 4: and 5 as before, and impresses upon the bullet the final accurate taper. In this last operation the core metal again is unconfined so that it may adjust itself to the action of the punch, and a final and accurate taper is given to the base of the bullet.

After the completion of the operation as shown in Figure 6, the bullet may be subjected to a final canneluring operation of any approved type and then attains its final form, as shown in Figure 7 It will be seen, therefore, that this invention provides an improved method for forming boat tail bullets. The base of the bullet is re-formed while the core metal is unconfined so that it may flow in response to the change of form of the jacket. The forming is accomplished in successive steps so that at each operation a comparatively small change of form is involved. Consequently reduced pressures on the punches and dies are practicable. After the base is formed to its proper taper, the core is condensed so as to render'it solid and compact; however, the jacket is not positively constrained while the core is being compressed. The base is then finally formed and sized. It will be evident that not only is the tendency for the jacket to buckle obviated, but these operations Will put much less strain upon the tools involved on account of the fact that, during the formation of the jacket, the core metal is free to flow, while during compression of the core the jacket is not positively restrained. In the employment of the means described, there is produced a jacket which is concentric upon all diameters, thereby increasing the accuracy of the bullet.

It is obvious that various changes may be made in the details without departing from the spirit of this invention; it is to be understood, therefore, that this invention is not limited to the specific details shown and described.

Having thus described the invention what is claimed is:

1. In the art of making jacketed boat tail bullets, the process of shaping the bullet comprising, frustoconically die-forming the tail of the jacket in successive stages While the core metal is unconfined, condensing the bullet endwise, and thereafter condensing the core metal therein.

2. In the art of making jacketed boat tail bullets, the process of shaping the bullet comprising, frustoconically die-forming the base of the bullet and condensing the bullet endwise while the core metal therein is unconfined, and thereafter positively condensing the core metal alone.

3. In the art of making jacketed boat tail bullets, the process of shaping the'bullet con1- prising, frustoconically die-forming the base of the bullet and condensing the jacket endwise while the core metal therein is unconfined, and thereafter radially contracting the base of the bullet while the core is unconfined.

4-. In the art of making acketed boat tail bullets, the process of shaping the bullet comprising, frustoconically die-forming the tail of the bullet and condensing the bullet endwise while the core metal therein is unconfined, thereafter positively condensing the core metal alone, and finally again contracting the base of the bullet.

5. In the art of making jacketed boat tail bullets, the process comprising, retaining a preformed jacket having core metal therein in a die whereby to maintain the shape of the body of the jacket, successively applying active external pressures to the tail portion thereof to radially contract the same While the core metal therein is unconfined, and subsequently applying active external pressure to condense the core metal within the jacket.

6. In the art of making jacketed boat tail bullets, the process comprising, retaining a preformed jacket having core metal therein in a die whereby to maintain the shape of the body of the acket, successively applying active external pressures to the tail portion thereof to radially contract the same while the core metal therein is unconfined, externally supporting the radially contracted tail to maintain the shape thereof, and applying positive pressure to the core metal to condense the same Within the acket.

In testimony whereof I aflix my signature this 13th day of August, 1926.

. STANISLAS ROUSSEAU.

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