Abstract:
A gauge for cartridges is disclosed. The gauge includes a gauge body defining an opening, a window, and receiving space. The opening and the receiving space share an axis and are in direct communication with each other. The window is in direct communication with the receiving space. The opening and the window are separated by a body portion of the gauge. Each gauge has a receiving space that is sized and shaped to correspond to a predetermined cartridge.

Description:
FIELD OF THE INVENTION 
     Gauges are used to determine if cartridges are within specification. Many bodies are used as cartridges, fired and reloaded. Gauges are often used to verify that the reloaded cartridges are within specification. 
     BACKGROUND OF THE INVENTION 
     Case gauges have been around in various forms for many years. The purpose of the gauge is to determine if the brass cartridge casing has been sized properly to work safely and correctly in a firearm. Each gauge is manufactured to be specific to a certain caliber of cartridge. These tools are commonly employed by reloaders, who are reusing their fired brass to make new ammunition. Brass casings will stretch or deform slightly after shooting, and in order to reuse the brass, the brass usually needs to be resized to some degree. To help the brass casing last longer, the amount of resizing should be kept to a minimum. 
     The headspace measurement is the critical length measurement to determine that the brass is sized correctly to fit into a firing chamber and fire. On bottleneck cases, typical in rifles, the headspace is measured from the point in the middle of the shoulder of the casing to the head (in proximity to where the primer is located). On straight wall cases, the headspace is measured from the mouth of the case to the head of the case. On a rimmed case, the headspace is measured from the rim top of the rim to the bottom of the rim or cartridge. The headspace measurement for various kinds of casings is well established. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Many aspects of the embodiments can be better understood with references to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the embodiments. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views. 
         FIG. 1  shows an embodiment of a gauge with a cartridge therein; 
         FIGS. 2-8  show different views of an embodiment of a gauge for use with cartridges that have a shoulder; 
         FIG. 9  shows a detail of  FIG. 6  and the different steps in an embodiment; 
         FIG. 10  shows an embodiment of a gauge with a cartridge therein 
         FIGS. 11-16  show different views of an embodiment of a gauge for use with cartridges that do not have a shoulder; 
         FIG. 17  shows a detail of  FIG. 13  and the different steps in an embodiment; 
         FIGS. 18 and 19  show examples of cartridges according to the prior art; 
         FIGS. 20-22  show an embodiment of a gauge. 
     
    
    
     DETAILED DESCRIPTION 
     The disclosure is illustrated by way of example and not by way of limitation in the figures of the accompanying drawings in which like references indicate similar elements. It should be noted that references to “an” or “one” embodiment in this disclosure are not necessarily to the same embodiment, and such references mean “at least one.” 
     Referring to  FIGS. 1 and 3 , a gauge is shown. The gauge comprises a gauge body  1 , and the gauge body  1  defines a receiving space  2  and a window  3 . The receiving space  2  is sized to accept a cartridge  4 . Depending on the caliber of the cartridge  4 , different section changes  21  and diameters are used to correspond to different bodies  41 , shoulders  42 , necks  43 , headspaces of the casing  47  and/or the bullets  45 . A cartridge  4  comprises the casing  47  and a bullet  45 . The casing  47 , comprises the body  41 , shoulder  42 , and neck  43 . 
     As can be seen in  FIGS. 2 and 4-6 , if required there can be more than one section change  21 . In many cartridges  4  for rifles, the cartridge&#39;s effective circumference changes at three points. There is the circumference of the body  41 , a shoulder  42  that extends to the neck  43 . The body  41  may have a fixed diameter, or it may have a slightly decreasing circumference as it approaches the shoulder  42 . The shoulder  42  typically has some length where it gradually decreases in circumference until it reaches the neck  43 . Thus the receiving space  2  defines a body section  211 , a gauge shoulder  212 , a neck section  213 , a freebore section  214 , a throat section  215 , and a barrel bore section  216 . It is to be understood that the receiving space  2  can have two or more sections that help determine if the cartridge  4  is within specification. Different caliber cartridges  4  and the specificity to specification will determine the number and lengths of the sections. The neck  43  can also have a decreasing diameter or a constant diameter. A neck section  213  is defined between to section changes  21 . The circumference of the receiving space  2  corresponding to the bullet  45  may stay consistent, the freebore section  214 , and/or decrease the further down it goes, the throat section  215 . The throat section  215  will decreases circumference until the barrel bore section  216 . Many bullets  45  have a conical shape. In some embodiments, the freebore section  214  will correspond only to a portion of the bullet  45  with a constant or a slightly varying diameter. 
     As can been seen  FIGS. 4-6 , the gauge body  1  defines a window  3 . The body portion  13  is located between the gauge face  14  and the window  3 . The window  3  extends from a position on the body section  211  to the foot  12 . The window  3  can be defined by a cutout that has an angle that is less than 180 degrees as measured from the center axis of the gauge body  1 . In some embodiments the cutout is about 30 degrees. In other embodiments, the cutout is about 90 degrees. The window  3  allows a user to view the interaction between the cartridge  4  and the gauge body  1 . The user is able to see the interaction between the body  41 , a shoulder  42 , the neck  43 , and the bullet  45  with the gauge body  1 . This is very important to identifying the problem if the cartridge  4  or casing  47  does not fit properly. While previously a user was able to tell that there was a problem with the cartridge  4 , as it did not fit properly in a gauge body  1 , however there was no way to specifically identify the problem. All that was known was the cartridge  4  did not meet specification. It was unclear whether it was a problem with headspace length, or a problem with the brass diameter being larger than specification. Even if it was known that the problem was the brass diameter, it was unclear as to whether it was the body  41 , shoulder  42 , the neck  43 , and/or the bullet  45 . By having the window  3  the user is easily able to identify the reason for the cartridge  4  for being out of specification. The user is also able to visually verify that the shoulder  42  is seated properly in the gauge. Thus the user is able to better identify and fix the problem. 
       FIGS. 7 and 8  show an embodiment of the gauge body  1  from the top and the bottom respectively. 
     As can be seen in  FIG. 9 , the gauge face  14  of the gauge body  1  has two different steps. Each of these helps verify that the headspace is within tolerances. The gauge face  14  will show the maximum allowable headspace for the firing chamber. The first step  131  will show the minimum allowable headspace for the firing chamber. The second step  132  will show the minimum allowable headspace for the cartridge  4 . This can be used to help adjust the case length to fit a specific firing chamber to minimize the rework. It can also be used to ensure that it is able to fit any firing chamber, for that caliber, as long as the cartridge  4 , when inserted in the receiving space  2 , is between the first step  131  and the second step  132 . Once the cartridge  4  is fired, the casing  47  can be inserted into the gauge body  1  and the actual headspace of the firing chamber can be inferred from the headspace length of the casing  47 . This can be used as a reference point for sizing the cartridge  4  in the future for a particular firing chamber as it is understood that there are variances in firing chambers even for the same caliber firearms. 
       FIGS. 10-17  are very similar to  FIGS. 1-9  except that the casing  47  does not decrease in diameter. As seen, only one section change  21  is present and that would correspond to where, within the specification of the cartridge  4 , the bullet  45  is exposed from the casing  47 . This is the location that the cartridge  4  should rest when placed in the gauge body  1 . There is a body section  211  and a freebore section  214  separated by the section change  21 . There are many cartridges  4 , handgun and rifle calibers, that employ cartridges  4  of this design. The window  3  is defined by the gauge body  1 . In some embodiments, the first step  131  and the second step  132  are present. 
       FIGS. 18 and 19 , show examples of cartridges  4 .  FIG. 18  shows a cartridge  4  with a casing  47  comprising a shoulder  42  and a neck  43 , in addition to a body  41  and a bullet  45 . As seen in  FIG. 19 , a cartridge  4  comprising of a body  41  and a bullet  45  is provided. It is understood that there are many kinds of cartridge  4  designs and that the receiving space  2  can be sized and shaped to correspond to the specification of that cartridge  4  and/or chamber. 
     Some embodiments can have texturing  15 , regardless of the corresponding cartridge  4 . While a diamond pattern is shown, many other regular or irregular texture patterns can be used. 
     To use the gauge, a user inserts a cartridge  4  into the receiving space  2  though the opening  22  of the gauge body  1 . In some embodiments, the cartridge  4  can only be inserted into the receiving space  2  via the opening  22  in the top the gauge body  1 . When a cartridge  4  is within its specification contact will be made along substantially the entire of the length of the casing  47 . The body  41 , and if present the shoulder  42  and the neck  43 , will be in continuous contact with the receiving space  2  of the gauge body  1 . The cartridge  4  is within specification when the cartridge  4  will sit within the gauge body  1 . The cartridge  4  is not within specification and will not sit properly within the gauge body  1  (e.g. an interference fit is established), the cartridge  4  extends above or below the gauge face  14  or the first step  131  respectively. It is understood that if the bullet  45  is also out of specification, the cartridge  4  will also not sit properly within the receiving space  2 . If there is a problem with the cartridge  4 , the window  3  allows the user to inspect the cartridge  4  in the receiving space  2 . The user is able to determine the specific location where the cartridge  4  is out of specification. 
       FIGS. 20-21  show an embodiment of a gauge having a gauge body  1  which extends to the end of the casing  47  of the cartridge  4 . It can be used to see if the casing  47  with or without a bullet  45  is within specification. A user can insert a spent casing  47  into the receiving space  2  to determine if the firing of the cartridge  4  has expanded the casing  47  or otherwise put it out of specification. This can also be done in a longer length gauge body  1 . While  FIGS. 20-22  show a receiving space  2  that corresponds to a casing  47  that has a shoulder  42 , it is understood that it can correspond to a casing  47  that does not have a shoulder. 
     A method of testing a cartridge  4  comprises the following steps: 
     S1, providing a gauge for a preselected caliber cartridge  4 ; 
     S2, placing a cartridge  4  of the preselected caliber into the gauge; and 
     S3, rotating the cartridge  4 . 
     In S1, the gauge may comprise of gauge body  1 , a receiving space  2 , and a window  3 . The window  3  can be defined by a cutout that defines an angle as measured from the center axis of the gauge body  1 . 
     In S3, the rotation of the cartridge  4  can occur inside the receiving space  2  or out of the receiving space  2 . Once rotated, the cartridge  4  is reseated in the receiving space  2 . The angle of rotation of the cartridge  4  should be such that the sides of the cartridge  4  that were exposed by the window  3  previously are no longer exposed when reseated. 
     Depending on the embodiment, certain of the steps of methods described may be removed, others may be added, and the sequence of steps may be altered. It is also to be understood that the description and the claims drawn to a method may include some indication in reference to certain steps. However, the indication used is only to be viewed for identification purposes and not as a suggestion as to an order for the steps. 
     It is to be understood, however, that even though numerous characteristics and advantages have been set forth in the foregoing description of embodiments, together with details of the structures and functions of the embodiments, the disclosure is illustrative only and changes may be made in detail, especially in the matters of shape, size, and arrangement of parts within the principles of the disclosure to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.