Full Length Cartridge Case Re-sizing

Abstract

A spent gun cartridge case is re-sized for its full length by placing it on a threaded support and then threadably joining the support-case assembly with a die. The case is freely supported on a thrust bearing so that the case rotates with the die as the members are threaded together. Alternately, the case and die are startingly joined and the resultant assembly threaded onto the support.

Description

BACKGROUND OF THE INVENTION

This invention relates to full length cartridge case re-sizing.

The reloading of rifle and handgun cartridges has become increasingly popular with shooters in recent years because of the rising cost of ammunition. In this respect, there is no reasonable limit to the number of times an ordinary brass cartridge case can be reloaded and re-used, and every reloading effects a substantial cost saving for the shooter. Moreover, the shells can be reloaded to the hunter's own specifications to provide the best results for his intended use, thus improving his shooting performance.

See my U.S. Pat. No. 3,134,293 as an example of a reloading device.

Before actual reloading can take place, it is important that the deformed brass cartridge case be re-sized. If the case is to be used in a gun different from the one in which it was originally fired, or if it is to be used in autoloading or pump action rifles, the case must be re-sized for its full length.

Previous full length re-sizing concepts, such as the use of a reloading press, have proven to be expensive and often less than satisfactory in results.

SUMMARY OF THE INVENTION

The present invention solves the afore-mentioned problems and provides inexpensive full length re-sizing with excellent results.

The concept of the invention is based on the utilization of a suitable support within which the cartridge case is positioned. The support-case assembly and a sizing die are then rotationally screwed together so that the case is forced into the die for its full length. This procedure utilizes great mechanical advantage.

DESCRIPTION OF THE DRAWING

The accompanying drawing illustrates the best mode presently contemplated by the inventor for carrying out the invention.

In the drawing:

FIG. 1 is an exploded view of the re-sizing device and cartridge case with parts in section;

FIG. 2 is a central sectional view showing the support and case assembled together prior to re-sizing;

FIG. 3 is a view showing a second method of preliminary assembly;

FIG. 4 is a central sectional view showing the support-case assembly and sizing die partially screwed together; and

FIG. 5 is a view showing the re-sizing completed.

DESCRIPTION OF THE PREFERRED EMBODIMENT

As shown in the drawing the invention is directed to full length re-sizing of a spent cartridge case 1 which in this embodiment has a reduced neck 2, tapered shoulder 3, elongated main body portion 4 of enlarged diameter, and a shellhead 5.

Case 1 is adapted to be positioned on support means comprising an elongated generally tubular press body 6 having a pair of internally threaded end portions 7, 8 joined by a central un-threaded portion 9. Each portion 7, 8 and 9 is of constant diameter, but central portion 9 is of larger diameter than end portion 7, and, in turn, end portion 8 is of larger diameter than central portion 9. Internal shoulders 10, 11 join the respective bore portions.

A rotatable thrust bearing 12 is positioned in central bore portion 9 and supports shellhead 5 during re-sizing. Bearing 12 is firmly held in position by a retainer 13 and by a threaded retainer screw 14 which is screwed into bore portion 8.

Prior to re-sizing, and in the method shown in FIG. 2, cartridge case 1 is placed in press body 6 so that head 5 rests on bearing 12. In the embodiment shown, the upper portion 15 of the press body wall is of substantial length, but slightly shorter than the main body portion 4 of case 1, so that the case extends slightly therebeyond.

For purposes of re-sizing, a sizing die 16 is provided. Die 16 comprises an elongated generally tubular heavy-walled member having an internal bore portion generally corresponding to the shape of case 1 and dimensioned to the exact desired final dimensions of the case. In the present embodiment, the internal die surface of die 16 includes a reduced neck 17, tapered shoulder 18 and elongated body portion 19. The major portion of the external wall of die 16 is of generally the same diameter as threaded portion 7 of press body 6 and is threaded to be received thereinto.

Portions of the outer walls of press body 6 and die 16 may be provided with respective wrench flats 20, 21 to facilitate the following operation.

The support-case assembly and die 16 are mutually joined by threading die 16 into press body 6, or vice versa. As the members gradually and threadably come together, as shown in FIG. 4, the die bore will engage case 1 and properly center it. Furthermore, die 16 will tightly engage case 1 and properly re-size its walls. In view of the tight fit between the die and case, and since the case is not tightly secured to its support, but rather is freely mounted on bearing 12, case 1 will rotate with die 16 as the members are brought together and the die forced over the full length of the case. Bearing 12 thus reduces the rotary frictional forces at shellhead 5.

A second method of assembly is shown in FIG. 3, wherein the upper end of case 1 is manually pressed into die 16 a short distance to provide a press fit start thereof. When die 16 is screwed into press body 6, shellhead 5 will subsequently engage bearing 12, and the remaining resizing operation is as shown in FIG. 4.

FIG. 5 shows the members when re-sizing is completed. They are then suitably disassembled and the case is ready for use in the usual well-known manner.

Various modes of carrying out the invention are contemplated as being within the scope of the following claims particularly pointing out and distinctly claiming the subject matter which is regarded as the invention.

Claims

I CLAIM:

1. Apparatus for full length re-sizing of a spent cartridge case having a shellhead, said apparatus comprising:

a. an elongated tubular press body for receiving the case therewithin,

b. means for supporting the case within said press body and with said means including bearing means mounted in said press body for freely supporting the case on its shellhead,

c. an elongated die having an internal bore portion generally corresponding to the shape of the case and dimensioned to the desired final dimensions thereof,

d. and mutually engagable thread means on said press body and said die,

e. said thread means being disposed so that rotatably threading said press body and die together will cause said die to be forced over the case to re-size the latter throughout its length,

f. said bearing means being rotatable so that, as said press body and die are rotatably threaded together, the case will rotate with said die and said shellhead will rotate together with said bearing means whereby rotary friction forces are reduced.

2. The apparatus of claim 1:

a. wherein said press body is provided with at least one internally threaded end portion joined to a central unthreaded portion,

b. wherein said bearing means comprises a thrust bearing disposed within said unthreaded portion,

c. and which includes means to secure said thrust bearing in place.

3. A method of full length re-sizing of a spent cartridge case having an elongated body and a shellhead, comprising the steps of:

a. placing said case with its shellhead freely mounted on a support having a rotatable base portion,

b. and rotatably threading a die onto said support whereby said die engages and rotates said case so that said shellhead and base portion rotate together so that the case is re-sized for its full length.

4. A method of full length re-sizing of a spent cartridge case having an elongated body, comprising the steps of:

a. providing a case re-sizing die and case support having a rotatable base portion,

b. press-fitting the upper end of said case into the die for a short distance to form an assembly,

c. and rotatably threading said die-case assembly onto said support in a manner so that said case engages said base portion and rotates therewith whereby rotary friction forces are reduced.