System for truing aspects of a cartridge case

A method and apparatus for truing a cartridge case with an apparatus including a frame defining a chamber and having a central axis, and a cartridge sleeve defining a cartridge passage with a passage surface for engaging the exterior surface of the body of the case, and a tool extending along the central axis of the frame with a tip end extending into the chamber. The frame may include a tool mandrel portion configured to mount the tool on the frame, and a sleeve mandrel portion configured to mount the cartridge sleeve on the frame. The sleeve mandrel portion may permit the cartridge sleeve and a cartridge case mounted thereon to translate with respect to the frame along the central axis of the frame, the sleeve mandrel portion permitting the cartridge sleeve and a cartridge case mounted thereon to rotate about the central axis with respect to the frame.

BACKGROUND

Field

The present disclosure relates to ammunition reloading apparatus and more particularly pertains to a new system for truing aspects of a cartridge case for improving the accuracy of target shots by the bullet of the cartridge.

SUMMARY

In one aspect, the present disclosure relates to a cartridge case truing apparatus for centering a cartridge case, and the cartridge case my have a mouth, a neck, a body, and a base opposite of the mouth, and an exterior surface on at least the body and the neck of the case. The apparatus may comprise a frame defining a chamber and having a central axis passing through the chamber, and a cartridge sleeve defining a cartridge passage for receiving the cartridge case. The cartridge passage may be defined by a passage surface for engaging the exterior surface of the body of the cartridge case when the case is inserted into the passage. The apparatus may further include a tool extending along the central axis of the frame with a tip end extending into the chamber of the frame. A tool mandrel portion may be configured to mount the tool on the frame, and a sleeve mandrel portion configured to mount the cartridge sleeve on the frame. The sleeve mandrel portion may permit the cartridge sleeve and a cartridge case mounted thereon to translate with respect to the frame along the central axis of the frame, and may permit the cartridge sleeve and a cartridge case mounted thereon to rotate about the central axis with respect to the frame.

In another aspect, the disclosure relates to a method of truing a cartridge case including providing a cartridge case having a mouth, a neck, a body, and a base opposite of the mouth, with the cartridge case further having an exterior surface on at least the body and the neck of the case. The method may further comprise providing an apparatus including a frame defining a chamber and having a central axis passing through the chamber, a cartridge sleeve having a cartridge passage defined by a passage surface, and a tool extending along the central axis of the frame with a tip end extending into the chamber of the frame. A tool mandrel portion may have the tool mounted thereon in a manner preventing rotation and translation of the tool with respect to the frame, and a sleeve mandrel portion configured to receive the cartridge sleeve. The method may further include inserting the cartridge case into the cartridge passage of the cartridge sleeve. The method may also include contacting the mouth of the cartridge case with the tool by rotating the cartridge case in the sleeve passage about the central axis with respect to the tool, and by translating the cartridge sleeve in the sleeve passage along the central axis to move the cartridge case toward the tip end of the tool. The translating of the cartridge case may be performed substantially simultaneously with rotating the cartridge case, and the method may also include advancing the cartridge case along the central axis to move the tip end of the tool into the neck of the cartridge case while rotating the case with respect to the tool.

DETAILED DESCRIPTION

With reference now to the drawings, and in particular toFIGS. 1 through 5thereof, a new system for truing aspects of a cartridge case embodying the principles and concepts of the disclosed subject matter will be described.

Reloading ammunition after usage is a popular way of reducing the cost of target practice through reusing the case of an ammunition cartridge by installing new propellant (or gunpowder), a new primer and a new bullet projectile on the used cartridge case. While a cartridge case may be reloaded and reused many times, each firing of ammunition causes the cartridge case to momentarily expand within the chamber of the firearm and as a consequence may tend to cause physical distortions of the cartridge case that persist even after firing. These distortions can produce variations in the manner in which the projectile is fired from the cartridge case, and as a consequence the accuracy and repeatability of the path of the projectile can vary significantly from one reloaded cartridge to another reloaded cartridge.

The applicant has recognized that many conventional devices have been developed for determining the distortions of the cartridge case, and reforming the cartridge case to a more uniform configuration to improve the accuracy and repeatability of the path of the projectile. However, such devices tend to focus upon resizing the mouth opening of the case and trimming away excess material from the case wall to seek a more uniform case wall thickness, without adequately addressing first centering the mouth and neck of the case with respect to the body of the case, after which further refinements, such as making the thickness of the case wall more uniform, may be attempted.

The applicant has devised an apparatus which is highly suitable for truing, or centering, the location of the mouth opening, and optionally also the neck, of the case with respect to the body, and the exterior surface of the body, to benefit the accuracy and repeatability of the path of the projectile fired from the cartridge case.

In one aspect, the disclosure relates to a cartridge case truing apparatus10for centering an ammunition cartridge case1, and may center the mouth2of the cartridge case1with respect to a body3of the cartridge case. Further, the apparatus10may be configured to center a neck4of the cartridge case with respect to the body3of the case. The cartridge case1may have a base5located opposite of the mouth2of the case, and an exterior surface6which extends about at least the body3and the neck4of the case. The neck of the cartridge case may also have an interior surface7.

In greater detail, the apparatus10may include a frame12which may define a chamber14that may be partially enclosed, and a central axis16may pass through the chamber. The frame12may be elongated in shape with a cartridge end18and a tool end19.

The apparatus may also include a cartridge sleeve20which defines a cartridge passage22which receives the cartridge case1to be trued. The cartridge passage22may be defined by a passage surface24which is configured to engage or abut the exterior surface6of the body of the case to constrain free movement of the body portion of the cartridge case with respect to the sleeve20, particularly in directions lateral to the central axis. While the exterior surface of other portions of the cartridge case may also be engaged by the sleeve20, typically the passage surface24is oversized with respect to the exterior surface6of the neck of the case to not engage or abut the neck of the cartridge case and thereby permit a degree of relatively free movement of the neck portion of the cartridge case with respect to the sleeve20in the lateral directions. The cartridge sleeve20may be elongated with a base end26and the neck end27with the cartridge passage22extending between the ends26,27. Typically, the length of the cartridge sleeve between the ends26,27and along the central axis16may be shorter than the length of the cartridge case to be trued by the apparatus such that the base5and at least a portion of the neck4extend beyond the respective base26and neck27ends of the sleeve. Extension of the base5of the cartridge case beyond the base end26of the cartridge sleeve20permits an engaging tool such as the jaws of a drill chuck to grip the base, as shown inFIG. 2, to rotate the cartridge.

The apparatus10may further include a tool30which has at least a portion which extends along the central axis16of the frame12. The tool30may have a tip end32which extends into the chamber14of the frame, and may be a free end for engaging the mouth2of a cartridge case to be trued. In some embodiments, the tool30may have an insertion portion34which has the tip end32of the tool and is configured to insert into the mouth2of the cartridge case, and may be configured to insert through the mouth and into the neck4of the case to engage the interior surface7of the neck. The insertion portion has an outer surface36for engaging the cartridge case to be trued.

In greater detail, the insertion portion34may include a main section38, and the outer surface36on the main section may have a substantially circular cross sectional shape with a primary diameter40that provides the outer surface with a substantially cylindrical shape. The primary diameter of the main section may be substantially uniform along the length of the main section, and the primary diameter may correspond to the desired diameter of the mouth2of the cartridge case, and also the desired diameter of the interior surface7of the neck4of the case. In some embodiments, the primary diameter may be just slightly larger than the nominal diameter of the opening at the mouth of the cartridge, so that the insertion of the free end of the tool into the mouth opening tends to slightly enlarge the diameter of the mouth opening. Illustratively, the primary diameter may be approximately 0.001 inch, although other dimeters may be used.

The insertion portion34may also include a tapered section42which is located toward the tip end32of the portion34, and the outer surface36of the tapered section may have a tapering diameter which becomes smaller toward the tip end and larger toward the main section38. The tapering may be substantially conical, although more rounded tapering may also be employed. The tapering of the diameter of the tapered section facilitates insertion of the tip end32into the mouth2of the cartridge case particularly when the mouth2is not completely centered on the central axis16. The tool30may further have a mounting portion44for mounting on the frame12, and the mounting portion may have an outer chuck surface46which is substantially cylindrical in shape although other shapes may be employed.

A tool mandrel portion50may be configured to mount the tool30on the frame, and may removably mount the tool on the frame to permit interchange of different tools on the frame to suit different sizes and types of cartridge cases. The mandrel portion50may be located adjacent to the chamber14of the frame. The tool mandrel portion may permit the tool to translate with respect to the frame12along the central axis16for positioning the tip end of the tool in the chamber, and in some embodiments may also permit the tool to rotate about the central axis with respect to the frame.

The mandrel portion may include a tool chuck52for receiving the mounting portion44of the tool when the tool is mounted on the frame. The tool chuck may include a tool passage54which extends into the tool mandrel portion from the chamber14, and may extend through the mandrel portion to the tool end19of the frame. The tool passage54may be centered on the central axis16of the frame to hold the tool in a centered relationship on the axis16. In some embodiments, the tool chuck52may include a tool securing element56which is configured to secure the tool30against translational movement and against rotational movement with respect to the frame12. Illustratively, the tool securing element56may comprise a set screw58positioned in a hole59which is in communication with the tool passage54such that advancement of the set screw in the hole brings the screw into contact with the chuck surface46of the mounting portion to resist movement, and conversely retraction of the set screw into the hole takes the screw out of contact with the chuck surface46to permit movement of the tool relative to the frame, as well as allowing removal of the tool from the frame. During use of the apparatus10, the set screw may typically be positioned against the chuck surface to resist translation and rotation of the tool with respect to the frame.

A sleeve mandrel portion60may be configured to mount the cartridge sleeve20on the frame, and may removably mount the sleeve20on the frame. The sleeve mandrel portion60may permit the cartridge sleeve20and a cartridge case mounted thereon to translate with respect to the frame along the central axis16, and may permit the cartridge sleeve and a case mounted thereon to rotate with respect to the frame about the central axis.

In some embodiments, the sleeve mandrel portion60may include a sleeve chuck62for receiving the cartridge sleeve20. The cartridge sleeve portion may include a sleeve passage64for receiving the cartridge sleeve, and the passage may be centered on the central axis. The sleeve passage may extend into the sleeve mandrel portion from the chamber14, and may extend through the sleeve mandrel portion to the cartridge end18of the frame. The sleeve chuck62may include a cartridge sleeve securing element66which is configured to secure the cartridge sleeve against translational movement and against rotational movement with respect to the frame. Illustratively, the cartridge sleeve securing element may comprise a set screw68which is positioned in a hole69formed in the sleeve mandrel portion which is in communication with the sleeve passage such that advancement of the set screw in the hole brings the screw into contact with the surface of the cartridge sleeve to resist movement of the cartridge sleeve with respect to the mandrel60, such as translation and rotation. Conversely, retraction of the set screw68into the hole69moves the screw out of contact with the surface of the sleeve20to permit movement of the sleeve relative to the frame. During use of the apparatus10, the set screw68may typically be positioned out of contact with the surface of the sleeve20to permit relatively free rotation of the sleeve and a cartridge therein with respect to the frame.

Optionally, a cutting tool70may be provided to remove material from the neck of the case to provide a more uniform thickness of the wall of the case forming the neck. Such removal of material from the neck of the case may be performed after the mouth and the neck of the case have been trued with respect to the body of the cartridge, and could be performed simultaneous with the truing of the neck although truing the elements of the cartridge first is preferred. At least a portion of the cutting tool70may be positioned or positionable in the chamber14and be configured to contact the exterior surface6of the neck4of the case in order to remove material from the exterior surface of the case. The cutting tool70may be provided with a sharpened point or edge72capable of cutting away material from the wall of the neck at relatively thicker portions of the wall to better match the thickness of the wall at the relatively thinner portions of the wall to achieve a more uniform wall thickness at all portions. Illustratively, the cutting tool70may be mounted on a saddle formed on the frame adjacent to the chamber which may permit some degree of adjustment of the positioning of the tool, and in particular the cutting edge72, with respect to the neck of the cartridge case.

In another aspect, the disclosure relates to a method of truing a cartridge case, such as is schematically depicted inFIG. 5, and may include centering the mouth and neck of the case with respect to the body of the case. The method may include providing a cartridge case truing apparatus having some or all of the elements described in this disclosure. The method may also include providing a cartridge case having one or more the features of a cartridge case described herein.

The method may include mounting the tool30in the frame12which may further comprise positioning the mounting portion44of the tool in the tool passage54of the tool mandrel50of the frame, and placing the tip end32of the tool in the chamber14of the frame such that the end is on the central axis of the frame. In preferred implementations of the method, the tool is secured against rotation and translation with respect to the tool mandrel portion and thereby the frame, when the apparatus is being used to true the cartridge case, and typically is only translated and/or rotated during setup of the apparatus for use and tear down of the apparatus after use.

Additionally, the method may comprise inserting the cartridge case1into the cartridge sleeve20, such as by inserting the cartridge case into the cartridge passage22of the cartridge sleeve, and such insertion may position a portion of the neck of the cartridge case beyond the neck end27of the cartridge sleeve and the base of the cartridge beyond the base end26of the sleeve.

The cartridge sleeve20may be mounted on the frame12, which may be accomplished by inserting the cartridge sleeve20into the sleeve passage64of the sleeve mandrel portion60of the frame. Such mounting positions at least a portion of the neck of the cartridge case in the chamber14of the frame with the mouth of the case generally centered on the central axis of the frame, but not necessarily entirely or perfectly trued on the central axis.

The method may continue by contacting the mouth2of the cartridge case with the tool30, which may be accomplished by pressing the mouth of the cartridge case against the tip end32of the tool, and penetrating the tapered section42of the insertion portion34of the tool into the mouth and neck of the cartridge case. Contacting the mouth and neck of the cartridge with the tool may be accomplished by rotating the cartridge case about the central axis16and with respect to the tool30. This may be accomplished by gripping the base of the cartridge case with a suitable tool or even the fingers of the user to cause rotation of the cartridge case. Such action may cause the cartridge sleeve20to rotate with the cartridge case and to rotate the cartridge sleeve with respect to the frame, although such actions may not necessarily result from the rotation of the cartridge base. Contacting the neck of the cartridge with the tool may also be accomplished by translating the cartridge case, along the central axis and with respect to the tool30, which may include translating the cartridge sleeve in the sleeve passage64of the sleeve mandrel portion of the frame. This may be accomplished by pushing the base5of the cartridge case in a direction toward the tool30. In some preferred implementations of the method, the translational movement of the cartridge case may be performed substantially simultaneously with rotational movement of the case as the case contacts the tool. Rotational movement of the case may be continued after translational movement of the case has been discontinued, while in many implementations translational movement of the case may not be performed without rotational movement.

The method may further include advancing the cartridge case along the central axis to move the tip end of the tool into the neck of the cartridge case, and may include moving the insertion portion of the tool into the neck of the case to contact the interior surface7of the neck. The translational movement of the case may be continued until substantially the entire interior surface of the neck is contacted by the tool, and rotation of the case may continue until it is determined that the mouth the neck have been trued with respect to the central axis, which may be indicated by sensing relatively less or decreasing resistance to the rotation of the case with respect to the tool.

Optionally, the method may include contacting a cutting tool70against the exterior surface of the neck of the cartridge case as the cartridge case is rotated to remove material from the exterior surface of the cartridge case and thus the wall forming the neck of the cartridge case. In some implementations, the cutting tool may travel along the exterior surface of the neck in a direction that is parallel to the central axis16to move material from the wall.

Completion of the method may include withdrawing the insertion portion of the tool from the neck portion and mouth of the cartridge case, and removal of the cartridge casing from the cartridge sleeve of the apparatus10.

It should be appreciated that in the foregoing description and appended claims, that the terms “substantially” and “approximately,” when used to modify another term, mean “for the most part” or “being largely but not wholly or completely that which is specified” by the modified term.

It should also be appreciated from the foregoing description that, except when mutually exclusive, the features of the various embodiments described herein may be combined with features of other embodiments as desired while remaining within the intended scope of the disclosure.

Further, those skilled in the art will appreciate that steps set forth in the description and/or shown in the drawing figures may be altered in a variety of ways. For example, the order of the steps may be rearranged, substeps may be performed in parallel, shown steps may be omitted, or other steps may be included, etc.

In this document, the terms “a” or “an” are used, as is common in patent documents, to include one or more than one, independent of any other instances or usages of “at least one” or “one or more.” In this document, the term “or” is used to refer to a nonexclusive or, such that “A or B” includes “A but not B,” “B but not A,” and “A and B,” unless otherwise indicated.