US3249980A - Swaging of bullets - Google Patents

Description

May 10, 1966 R. H. EISENMAN SWAGING OF BULLETS Filed Feb. 24, 1964 (W /6% ATTORNEY S United States Patent Filed Feb. 24, 1964, Ser. No. 346,668 13 Claims. (Cl. 291.22)

This invention relates to swaging of bullets such as those used in firearms of 22 to 45 caliber, for example. Among the objects of the present invention is the provision of a novel method of swaging high quality bullets of the above type in a relatively simple manner.

Additional objects of the present invention include the provision of bullets obtained by the foregoing swaging as well as novel apparatus in which the swaging operation is easily carried out.

The above as well as additional objects of the present invention will be more fully appreciated from the following description of several of its exemplifications, reference being made to the accompanying drawings wherein:

FIG. 1 is a somewhat schematic side view, with parts broken away, of one form of a bullet swaging apparatus according to the present invention;

FIG. 2 is a sectional view of the apparatus of FIG. 1 taken generally along the line 2-2; and

FIG. 3 is a detail view of theswaging elements of the apparatus of FIG. 1 shown in fully compressed condition along with a bullet formed by the swaging.

Skilled pistol shooters and the like require very high quality bullets in order to achieve the greatest shooting accuracy. The ordinary commercially available bullets, whether machine loaded into cartridges or hand loaded, do not completely fulfill the requirements of such experts. There has accordingly been considerable development in the manual swaging of bullets which each expert can carry out himself in an attempt to make 'his bullets exactly alike. factory.

v .It has now been discovered that a lead bullet of excellent characteristics is readily manufactured by swaging it with a pressure of at least 60 tons persquare inch and with such pressure distributed over the entire surface of the bullet except for gaps no wider than about two thousandths of an inch.

In order to assure accurate weights of bullets swaged on a volume production basis, the charge of bullet-forming material submitted to the swaging is in practice made a little larger than thedesired final mass, with the swaging arranged to squeeze out the surplus mass generally in the form of a cylindrical riser about inch in diameter. Unavoidable variations in supplying the charge are then made to appear as variations in the amount of riser, the

Such manual swaging has not proven very satisremainder of the bullet being then generally of substantially unvarying mass. The riser is then removed, leavmg the desired bullet. The amount of pressure required to swage bullets under those conditions is not very large ilnd can be as little as 25 tons per square inch, or even ess.

According to the present invention swaging of the bullet 1s carried out between side blocks and a nose'die, the nose die fitting with from'about /2 to two thousandths of an inch clearance between the upper portions of the side blocks, and the nose die is forced against a slightly excessive bullet-forming mass in the blocks to form in one operation a bullet that is complete and has excess mass solely in the form of a small amount of very thin flashing at the location where the nose die has said clearance.

A pressure of at least about 60 tons per square inch makes the above swaging a relatively simple operation.

The amount of flashing formed is particularly small and can be generally between /3 and 1 grain per bullet. Lubof the bullet height, although if desired more than one Patented May 10, 1966 r ce rication grooves can be provided in the bullet Without any further treatment by merely suitably shaping the side blocks.

The very thin condition of the flashing formed in the above manner leaves it readily broken off as by a rotating tool that is brought down against the nose of the swaged bullet, and chews up the flashing without removing any mass from the body of the bullet.

For large-scale manufacturing operations a bullet swaging apparatus according to the present invention can have assembly means connected to assemble the side blocks before the nose piece is forced against the bullet-forming mass, and to separate the side blocks after the swaging is completed, with the side blocks carrying an ejection device for ejecting the swaged bullet when the blocks are separated.

Because of the high order of accuracy needed, the side blocks preferably have mating surfaces bounding the bullet-forming cavity, and the remaining surfaces of these blocks are relieved to keep from interfering with the mating.

Turning now to the drawings, the apparatus of FIG. 1 has a loading chute 10 in which a number of individual cylindrical bullet-forming masses or changes 11, 12, 13, 14 and 15 are introduced as by an automatic feeder, not shown. These masses can be of any shape but cut lengths of rod or wire are easily 'fed in this way. These lengths and bottom of the bullet are defined. Soxassem-bled, the

advancing of arm 22 will cause the leading bullet-forming mass or cut length 11 to drop into the swaging cavity. To better guide the bullet-forming masses in their travel, a pair of spring-loaded guide arms 40 can be fixed in place to engage the sides of the masses as they move along the chute 10 and over the cutout 25.

A nose die 44 is arranged to reciprocate vertically into and out of the swaging cavity and is propelled into the cavity with a force sufficient to develop the desired swag ing pressure. The lower face 46 of the nose die is contoured to provide a swaged bullet nose of the desired shape. In the particular illustration the face 46 is re cessed to provide a bullet nose of so called wad-cutter type.

The lateral margin 50 of the nose die 44 around its bullet-engaging face 46 is dimensioned to provide a clearance 52 of from /2' to two thousandths of an inch with respect to the walls of the bullet-forming cavity in the side blocks. This clearance extends around the entire periphery of the nose die and provides all that is needed to allow flashing 55 to be squeezed out during the swaging.

In the illustrated apparatus each side block 31 is pro vided with an ejection pin 58 having an enlarged head 60 shaped to form a portion of the surface of cavity 33 against which the bullet is swaged. As more fully shown in FIG. 2, such ejection pin extends through a passageway in its block and carries an enlarged foot 62 extending out from the back surface of the block. A spring 64 between the block and foot 62 biases the ejection pin to its fully seated position illustrated in FIG. 2 so that its head 60 effectively becomes a portion of the bullet-shaping swaging cavity. One such ejection pin can be fitted in each of the side blocks preferably near the mid-point 3 such pin can be fitted in some or all of the blocks in that or any other location.

A toggle linkage represented at 68 connects each block with a back-up support 70 and is also arranged for operation by some type of vertical movement that actuates the nose die 44, to push the blocks together in face-to-face engagement and subsequently to withdraw the blocks from each other. The central pivot 69 of the toggle linkage can to this end be connected to the ram of a press, which ram is also arranged to directly force nose die 44 into the swaging cavity.

The toggle mechanism can be connected to the side blocks at a different level than that at which the ejection pins are located so that these components do not interfere with each other. Accordingly, when the side blocks are pulled open by their toggle mechanisms, the feet 62 of the ejection pins engage the backing supports '70 thus driving the ejection pins toward each other and pushing the swaged bullet out from whichever cavity half it might stick in.

A feature of the present invention is that the high accuracy of the block engagement can be more readily maintained by relieving all portions of the block faces that do not come into mating engagement. Thus, as shown in the figures, the side margins 71 and the bottom margin 72 of the cavity 33 are the only parts of the block faces that mate and the surfaces 74, 75on either side of the side margins as well as the surface 76 below the bottom margin 72, are recessed away from mating engagement by at least several thousandths of an inch. It is helpful in this connection to extend the mating portions of side margin 71 up above the bullet-defining portion of the cavity to the location '78 where the nose die engages the blocks. .In other words, mating is preferred to take place at all surfaces 71, 72 and 78, with all other parts of the block faces relieved somewhat.

Bullets are directly swaged with lubrication grooves according to the present invention by providing the cavities 33 with lands such as indicated at 81, 82 and 83, shaped to form the desired grooves. More or fewer grooves can be provided. The bullet is also preferably formed with a slight tapered or beveled base, as shown by the fillet 85 around the lower margin of the cavities.

The side blocks are supported against the downward swaging force applied to nose die 4-4, by a floor 87 which has an opening 89 under the bullet-forming cavity. When the side blocks are pulled apart and the swaged bullet ejected, it falls through this opening and through a pocket 91 in an indexing head 93, to rest against a stationary table 95. Indexing head 93 is pivoted for rotation about a central post 97 on the table and carries a plurality of pockets 91 equally spaced radially around its pivot. Each pocket is accurately located and can have its upper portion tapered or flared to assure that a falling bullet finds its way accurately into position in these pockets. A pair of spring arms 99 can be provided at cut-away portions at the bottom of each pocket 91 to frictionally engage a bullet when it is in the pocket and help accurately fix its position.

The pockets 91 are shown as arranged so that when one is located at A under opening 89, another is at B under a deflasher tool 101, and a third at C under a discharge rod 103. At location C the table has a cutaway 107 shaped to permit a bullet in the pocket to be pushed down and out of the indexing assembly by downward movement of the discharge rod.

Another indexing pocket can be provided and located under a tamping rod similar to discharge rod 103 but arranged to merely push down against a bullet in this location to make sure it is fully seated against the table 95 and ready for the deflashing operation. Indexing of the indexing head is synchronized with the swaging action as by conventional mechanical or electrical linkage that causes the head to rotate one step each time the nose die 44 is retracted. A solenoid 102 with a stepping pawl 104 biased by spring 106 to a position in engagement with one of a set of teeth 108 in the indexing head will, upon actuation, step the head around and then return to the illustrated position where it is ready for the next step.

Deflashing tool 101 has an inverted cup-shaped head 110 with a depending skirt arranged to fit against the upper margin of a bullet and thereby accurately guide the head over the bullets nose. A breaking shoulder extending inwardly of the skirt is thus brought into engagement with the flashing 55 on the bullets nose. The deflasher tool is rotated in the direction shown by arrO-W as by a shank 116 held in a drill press type spindle so that the head can be reciprocated vertically as it is rotated. One or more breaker teeth 117 can be provided in shoulder 114 to help the breaking action without tending to dig in or cut the body of the bullet below the flashing. This, coupled with an accurate adjustment of the limit to which the breaker head is lowered, keeps from marring or removing any material from the body of the bullet. The teeth 114 can be made of relatively hard material such as tungsten carbide to maintain their accuracy by reducing their wear. The head can also have a number of cut-outs as shown at 120 for example, to more readily permit discharge of broken pieces of flashing.

Under cut-away 107 of table 95 is a bullet burnisher generally indicated at which can be of conventional construction including an accurately dimensioned neck 132, a tapered intake guide 134, and a set of lubricating grooves 136. These grooves are manifolded at 138, and connected to a lubricating pump which can be mechanically, hydraulically, pneumatically or electrically actuated to pump one stroke each time a bullet is in the lubricating position illustrated. Discharge rod 103 is reciprocated vertically to push a bullet from indexing position C through the burnishing neck into lubricating position.

In operation the apparatus of FIG. 1 can have its advancing arm 22, nose die 44, block actuating linkages 58, deflasher head 101 and discharge rod 103 all operated as by the ram of a single press, and interlinked to also operate the advancing action of the indexing table as well as the lubricator. All these elements can also be interlinked with a cutter mechanism that cuts and supplies the bulletforming charges to chute 11. However, such cutting can generally be performed at a rate several times as fast as the swaging so that it is usually preferable to have a single cutter mechanism arranged to feed several swaging assemblies.

With an apparatus interconnected in the foregoing manner, a downstroke of the pressram accomplishes the following in the indicated order:

(A) First closes the side blocks 31;

(B) Then actuates arm 22 to push a bullet-forming charge into the cavity of the closed blocks;

(C) Then pushes the nose die 44 down against the charge;

(D) During stage (C) the discharge rod also pushes a deflashed bullet into burnisher 130, thus pushing a previously burnished bullet out the bottom of the burnisher;

(E) Also during stage (C) the deflasher head is lowered into deflashing position and cleans up a bullet;

(F If a tamper is used before deflashing, the tamper is also operated during stage (C);

(G) The lubricator 140 is given a lubricating stroke after stage (D) is completed.

At the completion of the ram downstroke, it can be promptly pulled back up to accomplish the following:

(H) Pull the nose die away from the swaged bullet in the block cavities; v v

(I) Then separate the blocks to cause the swaged bullet to be ejected and to fall into the indexing pocket at position A;

, (J) During combined stages (H) and (I) the discharge rod 103, deflashing head 101 and any tamping rod are raised away from indexing head. The advancing arm can also be retracted at this time;

(K) The indexing table is then indexed to its next position;

(L) The lubricator 140 is then retracted to prepare for its next stroke.

The above apparatus can be operated to swage and complete bullets at a rate of 6,000 an hour or even faster. This production rate can-be multiplied as by having the die blocks arranged to provide cavities for two or more bullets with all other structures duplicated so that at a single stroke a plurality of bullets are swaged and finished.

The bullets of the present invention are of particularly high quality because of the very high pressures used in the swaging These pressures are easily supplied as for example by using a thirteen ton press to swage a .38 caliber bullet that has a diameter of 0.357'inch. The pressure thus developed is slightly over 100 tons per square inch. Also because the flashing is formed across a gap no wider than twothousandths of an inch, the swaging pressure is applied to substantially the entire bullet.

Stated differently, with prior art swaging to form relatively thick risers, the flow of the bullet mass into the thick riser is accomplished at relatively low pressures so that there is no way to get such prior art pressures to build up any higher.

Because of the very high pressures of the present invention, the bullets thus produced have a more compact and uniform structure in which no voids Whatever can be found. These bullets demonstrate an unusually high order of accuracy in test firings.

The bullets of the present invention can be made in any desired size and shape. The apparatus of the present invention can have its nose die readily replaced to swage different noses on bullets. It is desirable to also have the discharge rod and any tamping rod provided with a bullet-engaging face shaped to match the nose of the bullet to avoid any misshaping action. 7

The bullets of the present invention are preferably made of lead alloys such as one containing from about 4 to 6% antimony, the balance lead. Such an alloy is relatively hard so that the swaged bullets are less easily damaged in handling. Also the bevel 85 at the base of the bullets of the present invention provides suflicient taper to more readily enable them to be inserted in a shell for comple tion of the final cartridge. Because of this greater ease of insertion there is less tendency for a portion of the bullet mass to be scratched away by the edge of the shell. This is also believed to be an important contribution to the unusual accuracy of these bullets.

The taper, particularly in combination with the perfectly flat nature of the remainder of the bullet base,

makes the 'bullets of the present invention highly suited for loading into cartridges by automatic high speed loading or reloading machines. They are in fact capable of being loaded at a. greater hourly rate of loading and with less malfunction than any other prior art mass production bullet. A highly eifective base taper is one that extends at an angle of 60 from the plane of the base and about 5 of an inch along the side of the bullet.

The bullets of the present invention can also be made of other materials such as lead containing more than 6% antimony or less than 4% antimony, or even pure lead, or lead containing tin or other alloying ingredients or mixtures of alloying ingredients.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is, therefore, to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

What is claimed:

1. In the process of swaging a bullet, the improvement according to which the swaging is carried out between side blocks and a nose die, the nose die fitting with from about /2 to 2 thousandths of an inch clearance between the upper portions of the side blocks, and the nose die is forced against a slightly excessive bullet-forming mass in the blocks to form in one operation a bullet that is complete and has excess mass solely in the form of a small amount of very thin flashing at the location where the nose die has said clearance.

2. The combination of claim 1 in which the excess mass weights between about A and 1 grain.

3. The combination of claim 1 in which the side blocks have lands that form lubricating grooves in the bullet during the swaging operation.

4. The combination of claim 1 in which the nose die is forced against the bullet-forming mass with a pressure of at least about 60 tons per square inch.

5. The combination of claim 1 in which the flashing is removed from the bullet by a rotating flashing breaker.

6. A bullet swaging apparatus having separable side blocks that assemble together to form an open-topped cavity defining the external shape of the sides and bottom of the bullet, a separate nose die defining the external shape of the bullet nose and having from /2 to 2 thousandths of an inch clearance with respect to the open top of the cavity, and forcing mechanism connected to force the die into the cavity by way of its open top to swage a bullet-forming mass in the cavity into a completed bullet that has excess mass solely in the form of very thin flashing at the location Where the nose die has said clearance.

7. The combination of claim 6 further including assembling means connected to assemble the side blocks before the nose piece is forced against the bullet-forming mass, and to separate the side blocks after the swaging, and the side blocks have ejection pins for ejecting the swaged bullet when these blocks are separated.

8. The combination of claim 6 in which the side blocks have mating surfaces bounding the cavity, and the remaining surfaces of the blocks are relieved to keep from interfering with the mating.

9. The combination of claim 6 further including a rotary flashing breaker and reciprocating elements connected to bring the breaker against the nose of a bullet 'after it is swaged to break off the flashing, and then retract the breaker away from the defiashed bullet.

10. An apparatus for automatically swaging bullets, said apparatus including a set of side blocks that assemble together to form an open-topped cavity defining the external shape of the sides and bottom of the bullet, a separate nose die defining the external shape of the bullet nose and having from /2 to 2 thousandths of an inch 'clearance with respect to the open top of the cavity, automatic actuating mechanism connected to (a) hold the side blocks separated with the nose die removed from the cavity, (b) assemble the side blocks, (c) drop a bulletforming mass into the assembled side blocks, ((1) force the nose die against the bullet-forming mass in the cavity to swage a complete bullet that has excess mass solely in the form of very thin flashing at the location where the nose die has the clearance, (e) retract the nose die and open the side blocks, and (f) eject the swaged bullet.

11. The combination of claim 10 in which the automatic actuating mechanism is further connected to bring a rotating flashing breaker against the nose of the swaged bullet to deflash it.

12. A lead bullet having a structure formed by compression at a pressure of at least 60 tons per square inch with pressure gaps of no more than about 2 thousandths of an inch.

13. The bullet of claim 12 in which the lead is an alloy containing about 4% to 6% antimony, and the base of the bullet has its edge tapered.

No references cited.

RICHARD H. EANES, JR., Primary Examiner.

Claims (1)

1. IN THE PROCESS OF SWAGING A BULLET, THE IMPROVEMENT ACCORDING TO WHICH THE SWAGING IS CARRIED OUT BETWEEN SIDE BLOCKS AND A NOSE DIE, THE NOSE DIE FITTING WITH FROM ABOUT 1/2 TO 2 THOUSANDTHS OF AN INCH CLEARANCE BETWEEN THE UPPER PORTIONS OF THE SIDE BLOCKS, AND THE NOSE DIE IS FORCED AGAINST A SLIGHTLY EXCESSIVE BULLET-FORMING MASS IN THE BLOCKS TO FORM IN ONE OPERATION A BULLET THAT IS COMPLETE AND HAS EXCESS MASS SOLELY IN THE FORM OF A SMALL AMOUNT OF VERY THIN FLASHING AT THE LOCATION WHERE THE NOSE DIE HAS SAID CLEARANCE.

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