Abstract:
A slide assembly capable of repeated reciprocal movement about an upper portion of a firearm having a firing pin assembly, including a firing probe tip for selectively contacting a chambered ammunition cartridge, includes a frame having a forward end and an aft end, the frame accommodating a barrel of the firearm along a longitudinal firing axis. An ejector port is formed in the frame and has a breech face against which an end cap of the ammunition cartridge abuts when in a firing position. A longitudinal firing probe bore is formed within the frame and extends from adjacent the aft end of the frame to adjacent the breech face, the firing probe bore also is in concentric alignment with the firing axis. The slide assembly further includes a probe tip bore in concentric alignment with the firing axis and extending between the breech face and the firing probe bore for allowing the firing probe tip access beyond the breech face and into the ejector port. An engagement slot is further formed in the firing probe bore for mating engagement with a lower key housing of the firing pin assembly, thereby rotationally securing the firing pin assembly in the firing probe bore.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     Some of the material disclosed herein is disclosed and claimed in the following issued U.S. Pat. No. 6,286,241, issued Sep. 11, 2001, entitled “FIRING CONTROL SYSTEM FOR NON-IMPACT FIRED AMMUNITION”; pending U.S. patent application Ser. No. 09/206,013, filed Dec. 4, 1998, entitled “FIREARM HAVING AN INTELLIGENT CONTROLLER”; issued U.S. Pat. No. 6,260,300, issued Jul. 17, 2001, entitled “BIOMETRICALLY ACTIVATED LOCK AND ENABLEMENT SYSTEM”; issued U.S. Pat. No. 5,717,156, issued Feb. 10, 1998, entitled “SEMI-AUTOMATIC PISTOL”; pending U.S. patent application Ser. No. 09/629745, filed Jul. 31, 2000, entitled “A SECURITY APPARATUS FOR USE IN A FIREARM”; pending U.S. patent application Ser. No. 09/642,753, filed Aug. 21, 2000, entitled “AN ELECTRIC FIRING PROBE FOR DETONATING ELECTRICALLY-FIRED AMMUNITION IN A FIREARM”; pending U.S. patent application Ser. No. 09/629531, filed Jul. 31, 2000, entitled “A TRIGGER ASSEMBLY FOR USE IN A FIREARM AVING A SECURITY APPARATUS”. pending U.S. patent application Ser. No. 09/629,532, filed Jul. 31, 2000, entitled “A BACKSTRAP MODULE CONFIGURED TO RECEIVE COMPONENTS AND CIRCUITRY OF A FIREARM CAPABLE OF FIRING NON-IMPACT FIRED AMMUNITION”; pending U.S. patent application Ser. No. 09/643,024, filed Aug. 21, 2000, entitled “A METHOD OF ASSEMBLING A FIREARM HAVING A SECURITY APPARATUS”; pending U.S. patent application Ser. No. 09/629,534, filed Jul. 31, 2000, entitled “AN AMMUNITION MAGAZINE FOR USE IN A FIREARM ADAPTED FOR FIRING NON-IMPACT DETONATED CARTRIDGES”; pending U.S. patent application Ser. No. 09/616,722, filed Jul. 14, 2000, entitled “AN ELECTRONICALLY FIRED REVOLVER UTILIZING PERCUSSIVELY ACTUATED CARTRIDGES”; pending U.S. patent application Ser. No. 09/616,696, filed Jul. 14, 2000, entitled “AN ELECTRONIC SIGHT ASSEMBLY FOR USE WITH A FIREARM”; pending U.S. patent application Ser. No. 09/616,709, filed Jul. 14, 2000, entitled “A FIRING MECHANISM FOR USE IN A FIREARM HAVING AN ELECTRONIC FIRING PROBE FOR DISCHARGING NON-IMPACT FIRED AMMUNITION”; pending U.S. patent application Ser. No. 09/616,722, filed Jul. 14, 2000, entitled “A FIRING PROBE FOR USE IN A NON-IMPACT FIREARM”; pending U.S. patent application Ser. No. 09/616,837, “A SECURITY APPARATUS FOR AUTHORIZING USE OF A NON-IMPACT FIREARM”; pending U.S. patent application Ser. No. 09/616,697, filed Jul. 14, 2000, entitled “A BACKSTRAP MODULE FOR A FIREARM”, which are hereby incorporated by reference as part of the present disclosure. 
    
    
     FIELD OF THE INVENTION 
     This invention pertains generally to firearms and, more specifically, to a slide assembly for a firearm which can house a firing pin assembly so as to maximize reliability and repeatability in operation and safety. 
     BACKGROUND OF THE INVENTION 
     Over the years, there has been a continuous effort to improve the security and operation of conventional firearms. Improvements in electronics technology has allowed certain mechanical firing systems and components in firearms to be replaced by electronic components. For example, a mechanical trigger bar is displaced by an electronic solenoid in U.S. Pat. No. 4,793,085, “ELECTRONIC FIRING SYSTEM FOR TARGET PISTOL”. In U.S. Pat. No. 5,704,153, for a “FIREARM BATTERY AND CONTROL MODULE”, a firearm using conventional percussion primers incorporates a processor into its ignition system. 
     Electronics have also been incorporated into ignition systems for firearms that use non-conventional primers and cartridges. U.S. Pat. No. 3,650,174, for “ELECTRONIC IGNITION SYSTEMS FOR FIREARM”, describes an electronic control system for firing electronically-primed ammunition. The electronic control of the &#39;174 patent, however, is hard-wired and lacks the multiple sensor interfaces of the programmable central processing unit that is found with the present invention. U.S. Pat. No. 5,625,972, for a “GUN WITH ELECTRICALLY FIRED CARTRIDGE”, describes an electrically-fired gun in which a heat-sensitive primer is ignited by voltage induced across a fuse wire extending through the primer. U.S. Pat. No. 5,272,828, for a “COMBINED CARTRIDGE MAGAZINE AND POWER SUPPLY FOR A FIREARM”, shows a laser ignited primer in which an optically transparent plug or window is centered in the case of the cartridge to permit laser ignition of the primer. Power requirements to energize the laser, as well as availability of fused and or laser-ignited primers are problematic, however. U.S. Pat. No. 5,755,056, for an “ELECTRONIC FIREARM AND PROCESS FOR CONTROLLING AN ELECTRONIC FIREARM”, shows a firearm for firing electrically-activated ammunition having a cartridge sensor and a bolt position sensor. The technology of the &#39;056 patent, however, is limited to a firearm with a bolt action. 
     Much of the effort in recent years to integrate electronics into firearms stems from a desire to effectively restrict the person or persons who are able to operate the firearm. There have also been numerous attempts to incorporate external, mechanical locking devices such as keyed locks which prevent movement of the trigger or firing mechanism. The downside of such external locking devices is that they are often cumbersome and timely to disable, and thus impractical for use on the person or in situations where the firearm must quickly be readied to fire. 
     None of the previously cited or discussed references disclosed firearms having slide assemblies which could house a firing pin assembly so as to maximize reliability and repeatability in operation and safety. The present invention is directed to such a firearm. 
     OBJECTS AND SUMMARY OF THE INVENTION 
     It is one object of the present invention to provide a firearm with a slide assembly capable of housing a firing probe assembly. 
     It is another object of the present invention to provide a firearm with a slide assembly capable of housing an electronic firing probe assembly. 
     It is yet another object of the present invention to provide a firearm with a slide assembly capable of electrically insulating an electronic firing probe assembly from the frame of the firearm. 
     It is still another object of this invention to provide a firearm with a slide assembly having a grounding apparatus. 
     It is still another object of this invention to provide a firearm with a slide assembly which may be reliably mass produced. 
     According to the present invention, a slide assembly capable of repeated reciprocal movement about an upper portion of a firearm having a firing pin assembly, including a firing probe tip for selectively contacting a chambered ammunition cartridge, includes a frame having a forward end and an aft end, the frame accommodating a barrel of the firearm along a longitudinal firing axis. An ejector port is formed in the frame and has a breech face against which an end cap of the ammunition cartridge abuts when in a firing position. A longitudinal firing probe bore is formed within the frame and extends from adjacent the aft end of the frame to adjacent the breech face, the firing probe bore also is in concentric alignment with the firing axis. The slide assembly further includes a probe tip bore in concentric alignment with the firing axis and extending between the breech face and the firing probe bore for allowing the firing probe tip access beyond the breech face and into the ejector port. An engagement slot is further formed in the firing probe bore for mating engagement with a lower key housing of the firing pin assembly, thereby rotationally securing the firing pin assembly in the firing probe bore. These and other objects, features and advantages of the present invention will become more apparent in the light of the following detailed description of best mode embodiments thereof as illustrated in the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an elevated schematic view of a pistol according to the present invention, shown with a barrel captured between a slide assembly and a pistol frame; 
     FIG. 2 Is an,exploded perspective view of the pistol of FIG. 1, showing a magazine and backstrap module disassembled from the pistol frame; 
     FIG. 3 is an enlarged plain view of the frame of FIG. 1 taken along lines  3 — 3 ; 
     FIG. 4 is a slightly enlarged and exploded perspective view of the slide assembly of FIG. 3, showing a firing probe, retainer, and front and rear sights; 
     FIG. 5 is an enlarged end view of the slide assembly of FIG. 4; 
     FIG. 6 is an enlarged bottom plan view of a rear end of the slide frame of FIG. 4; 
     FIG. 7 is an enlarged sectional view of the slide assembly of FIG. 4, taken along lines  7 — 7 ; FIG. 
     FIG. 8 is an enlarged schematical and generally bisected plan view of the pistol of FIG. 1, illustrating a cartridge moving toward camming engagement with the firing probe; 
     FIG. 9 is a frontal perspective view of a second embodiment of the slide assembly of FIG. 1, showing a breech face bushing removed from the slide frame; 
     FIG. 10 is an enlarged sectional view of the slide assembly of FIG. 9, taken along the lines  10 — 10 ; 
     FIG. 11 is a view similar to that of FIG. 10, except shown with the breech face bushing recessed within a breech face; 
     FIG. 12 is a view similar to that of FIG. 10, except shown with the breech face bushing protruding from the breech face; 
     FIG. 13 is an exploded perspective rear view of a third embodiment of the slide assembly of FIG. 3, shown with a breech face insert removed from the slide frame; 
     FIG. 14 is an assembled and enlarged broken-away cross-sectional view of the slide assembly of FIG. 13, taken along the lines  14 — 14  to illustrate installation of the breech face insert; 
     FIG. 15 is an exploded perspective rear view of a fourth embodiment of the slide assembly of FIG. 1, showing a breech face bushing and a breech face insert; 
     FIG. 16 is an assembled cross-sectional view of the breech face insert and breech face bushing of FIG. 15, shown prior to a final manufacturing step and installation in the slide frame; 
     FIG. 17 is an assembled cross-sectional view of the slide assembly of FIG. 15, taken along lines,  17 — 17 ; 
     FIG. 18 is an enlarged frontal perspective view of a fifth embodiment of the slide assembly of FIG. 1, shown with its frame cutaway to illustrate a breech face bushing and bushing retainer; 
     FIG. 19 is an exploded perspective view of the slide assembly of FIG. 18, shown slightly reduced in size; 
     FIG. 20 is an exploded rear plan view of the slide assembly of FIG. 18; 
     FIG. 21 is an enlarged cross-sectional view of the slide assembly of FIG. 20, taken along the lines  21 — 21 ; 
     FIG. 22 is an enlarged, exploded and cut-away perspective view of the firing probe assembly of FIG. 4; 
     FIG. 23 is an enlarged, exploded and cut-away perspective view of a second embodiment of the firing probe shown in FIG. 4; 
     FIG. 24 is a schematical perspective view of the backstrap module of FIG. 2, shown with an array of electronic components mounted to a rigid circuitboard secured within a two-piece module housing; 
     FIG. 25 is a frontal perspective view of the backstrap module of FIG. 24, shown reduced in size; 
     FIG. 26 is a rear perspective view of the backstrap module of FIG. 25; 
     FIG. 27 is a slightly enlarged bottom plan view of the backstrap module of FIG. 26; 
     FIG. 28 is a schematic plan view of one embodiment of the rigid circuitboard of FIG. 24, shown without the electronic components and prior to installation in the module housing; 
     FIG. 29 is an enlarged schematic elevational view of the backstrap module of FIG. 24, shown from the left side and the module housing shown in phantom; 
     FIG. 30 is an exploded perspective view of the backstrap module of FIG. 26; 
     FIG. 31 is a view similar to that of FIG. 29, except shown enclosing a second embodiment of the rigid circuitboard; 
     FIG. 32 is a plan view of the rigid circuitboard of FIG. 31, shown without electronic components mounted thereon and prior installation in the module housing; 
     FIG. 33 is an enlarged rear perspective view of the pistol of FIG. 1, illustrating a ground contact engaged with a terminal of the backstrap module and a firing probe contact engaged with a probe terminal; 
     FIG. 34 is an enlarged perspective view of the backstrap module of FIG. 29, shown schematically in proximity with a trigger assembly; 
     FIG. 35 is an exploded perspective view of the trigger assembly of FIG. 34, shown schematically and orthogonally with a microswitch and magnetic sensor; 
     FIG. 36 is an assembled cross-sectional view of the trigger bar of FIG. 35, taken along lines  36 — 36  and illustrating lines of magnetic flux produced by the magnet; 
     FIG. 37 is a graphical representation of the magnetic flux of FIG. 36 versus distance from the magnetic sensor; 
     FIG. 38 is an enlarged cut-away perspective view of an alternate embodiment of the backstrap module of FIG. 2, shown with a trigger bar engaging a guide post and positioned against a cam; 
     FIG. 39 is an exploded perspective view of various components within the backstrap module of FIG. 38; 
     FIG. 40 is an exploded perspective view of the magazine of FIG. 2; and 
     FIG. 41 is an enlarged perspective view of the underside of the magazine of FIG.  40 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to FIGS. 1-3, a firearm of the present invention is configured in the form of a pistol  10  which includes a unitary frame  12 , and a trigger  14  hung conventionally on the frame  12  by a transverse pin  16  for pivotal fore and aft movement therein. A barrel  18  has a bore  19  with a firing axis  20 , and is fixed medially of forward and rear ends  21 ,  22  of the frame  12 . 
     The frame  12  has an upwardly-open channel  24  extending over the length of the frame  12  from the forward end  21  to the rear end  22  thereof, and includes a pair of rails  26  on each upper edge of the frame  12 , the rails  26  being spaced apart and configured in a known manner to receive a slide assembly  28  adapted for reciprocal, sliding movement along the frame  12 . 
     The slide assembly  28  includes forward and aft ends  30 ,  32 , the forward end  30  being retained, supported and guided during movement by the interrelationship of the barrel  18  and slide assembly  28 . In that regard, an aperture  34  is provided through a front end wall  36  of the slide assembly  28  and which is adapted to receive therethrough the muzzle end of the barrel  18 . 
     For a complete discussion of the forward end  30  of the slide assembly  28 , and its functional relationship with the frame  12  and the barrel  18 , refer to the semi-automatic pistol of U.S. Pat. No. 5,717,156, which was issued on Feb. 10, 1998, assigned to the same assignee as this application, and is hereby incorporated by reference as part of the present application. 
     A retainer  38  is inserted into the aft end  32  of the slide assembly  28  and acts with the aperture  34  to retain the slide assembly  28  in its assembled and parallel relationship to the rails  26  of the frame  12 , and guide its reciprocal, longitudinal motion therealong which occurs whenever the pistol  10  is fired. The slide assembly  28  has a breech face  40 , which forms a firing chamber  42  when engaged against the breech end of the barrel  18 . As the slide assembly moves rearward on the frame  12  after firing, the firing chamber is exposed to an ejector port  44  of the slide assembly  28 , through which spent cartridges are ejected by a conventional ejector  46 . 
     The pistol  10  is configured with an array of sensitive electronic components which accomplish two broad objectives to protect the firearm from unauthorized use; and to provide a firing signal that is sufficient to ignite an electrically-fired ammunition. In general terms, firearm components must be robust to endure the hostile environment encountered during normal use, especially in the area of the breech face  40 . The environment of the breech face  40  is especially hostile, and effective integration of electronic components therein presents numerous concerns. 
     One concern is the long-term effect of contamination build-up that results from normal use of the firearm. If the contaminants are electrically conductive, the transmission of electronic signals may be adversely effected after extended periods of use without proper firearm maintenance. For instance, as metallic cartridges are scraped over the breech face  40  when loaded into and ejected from the firing chamber  42 , each cartridge deposits a small amount of casing material in the area of the breech face  40 . The build-up of these metallic deposits around insulated electrical paths can compromise the transmission of electrical signals. 
     Another concern is the cumulative effect of highly repetitive impact, sheer, and frictional forces which are created by the loading, firing, and ejecting of cartridges. The breech face  40  bears a majority of the large recoil force generated by firing a cartridge, so the components must be durable and resistant to wear to ensure long-term, consistent operation of the pistol  10 . 
     To protect the array of electronics, the rear end  22  of the frame  12  is adapted to receive a backstrap module  50 . Together, the backstrap module  50  and frame  12  form an ergonomically-designed pistolgrip  58  which extends downwardly and rearwardly relative to the forward end  21  of the frame  12 . A chamber  54  extends vertically through the frame  12  with a known configuration that receives an ammunition magazine  56  in a direction generally indicated by arrow  57 . 
     The backstrap module  50  is positioned on the frame  12  by means of complementary pairs of dovetails and dovetail receivers. The rear end  22  of the frame  12  includes a pair of upper dovetails  62  and a lower dovetail receiver  64  which are configured, oriented, and positioned to cooperate, respectively, with a pair of upper dovetail receivers  66  and a pair of lower dovetails  68  of the backstrap module  50 . 
     The backstrap module  50  is moved into position on the frame  12  by engaging its lower dovetails  68  with the lower dovetail receiver  64  of the frame  12  in the direction of arrow  57 . As the backstrap module  50  is moved onto the frame  12 , the upper dovetail receivers  66  receive the upper dovetails  62  of the frame  12 . A transverse pin bore  80  extending transversely through the backstrap module is brought into alignment with a pair of frame mount holes  76  on the frame  12 . A spring pin  81  is then inserted through the aligned holes to secure the backstrap module  50  to the frame  12 . The spring pin  81  is sized to fit tightly through the pin bore  80  and snugly through the frame mount holes  76 , so as not to damage the mount holes  76 . The pin bore  80  has a metallic sleeve which receives the spring pin  81  and avoids damaging the material of the backstrap module  50 . 
     Several embodiments of the slide assembly are described below, each of which has a different breech face and/or firing probe assembly configuration. The embodiment shown in FIGS. 4-6 is considered to be the best mode embodiment. 
     Referring to FIGS. 4-6, the slide assembly  28  includes a steel slide frame  82 , the retainer  38 , a firing probe assembly  84 , and conventional front and rear sights  86 ,  87 . The slide frame  82  includes the breech face  40 , an elongated, cylindrical firing probe bore  88 , and the ejector port  44 . The breech face  40  is oriented perpendicular to the firing axis  20  and includes a tip bore  89  which extends along the firing axis  20  through the breech face  40 . The firing probe bore  88  is counterbored on the firing axis  20  from the aft end  32  of the slide frame  82  and forms an annular probe seat  90 . 
     The aft end  32  of the slide frame  82  includes a conventional retainer channel  91  vertically below the frame  82 . The retainer  38  has a plunger bore  92  defined generally on the firing axis  20  and adapted to slidably receive a spring-loaded end cap plunger  94  of the firing probe assembly  84 . The firing probe assembly  84  is held securely within the firing probe bore  88  by a C-clip  96  engaged within a C-clip groove  98  of the slide frame  82 . To facilitate assembly, a slight gap is maintained between the firing probe assembly  84  and the C-clip  96 . The slide frame  82  has a slot  99 , or relief, that is configured to receive a lower housing  100  of the probe assembly  84 . 
     Referring to FIGS. 7-8, the firing probe assembly  84  includes a hardened-steel, spring-loaded probe tip  101  biased in the forward direction through the tip bore  89 . The probe tip  101  is forced against a cartridge  102  with a maximum spring force of two pounds, (the spring configuration is discussed in detail below in connection with the firing probe assembly which electrically engages, or contacts, the cartridge  102  captured against the breech face  40  in the firing chamber.) The spring force enables the probe tip  101  and cartridge  102  to rub together during loading and unloading in such a manner as to cause wiping or self-cleaning thereby enhancing electrical contact properties. 
     Because the probe tip  101  is meant to conduct electricity only to the cartridge  102 , and the breech face  40  is metallic, the probe tip  101  is coated with a ceramic material to electrically-insulate itself from the slide frame  82 . Only a distal portion  104  is left uncoated so that electrical continuity is maintained between the cartridge  102  and firing probe assembly  84 . The distal tip portion  104  has a radius of approximately 0.020 inches and extends beyond the breech face  40  by a distance of approximately 0.040 inches when the tip  101  is in its firing position. This ensures that there will be positive electrical contact between the firing probe tip  101  cartridge  102  produced by the aforementioned spring force. 
     The slide embodiments of the assembly contemplate use of a cartridge  102  fitted with a non-impact primer  106  such as that developed by Remington Arms Company and referred to as the Conductive Primer Mix described in U.S. Pat. No. 5,646,367. The primer  106  is imbedded within, and concentrically aligned with, the cartridge  102 , and is designed to detonate when an electrical signal of a predetermined voltage is applied to it. An end cap  112  forms a contact surface that is slightly recessed within the end of the cartridge  102  and forms a dimple which receives the distal portion  104  of the probe tip  101 . 
     The cartridge  102  is fed into the firing chamber in a direction that is substantially perpendicular to the firing axis  20  when the slide assembly  28  is drawn back rearwardly, so as to position the ejector port  44  above the magazine  56 . In a camming action, a beveled edge  118  of the cartridge  102  contacts and depresses the spring-loaded probe tip  101  within the breech face  40 . The probe tip  101  is then pushed forwardly toward its firing position, which is against and within the dimple of the cartridge primer  106 . In their respective firing positions, the firing probe tip  101  and the cartridge  102  remain in contact with each other while in the firing chamber  42 . 
     The aforementioned camming action of cartridges into the firing chamber  42  requires the firing probe to be spring-loaded. If the probe  101  was not spring-loaded, it could not retract within the slide frame  82 , and the edge  118  of the cartridge  102  would jam against the firing probe  101  and the cartridge would fail to chamber. Spring-loading the firing probe also avoids having to configure the slide assembly and/or firing apparatus with mechanical or manual means of engaging the loaded cartridge. 
     As is common with firearms, normal use leaves contaminants, including lubricants, metal cartridge shavings, and by-products of burnt gunpowder and primer, deposited over much of the firearm. These contaminants can accumulate on the probe tip  101  and/or the breech face  40 , and possibly cause a short in the electrical path between the firing probe assembly  84  to the cartridge  102 . Care must be exercised to prevent excessive wear of the ceramic coating from the probe tip  101  after extended use, which may increase the risk of a short circuit. 
     Referring to FIGS. 9-10, slide assembly  228  includes a slide frame  282  having a breech face  240  with a countersunk bushing bore  233  on the firing axis  20  which is configured to receive a ceramic, annular breech face bushing  231 . The depth of the bushing bore  233  coincides with the axial thickness of the bushing  231  so as to produce a flush breech face  240  after assembly. The bushing  231  has a probe tip bore  289  on the firing axis  20  to slidably receive a probe tip  201  of a probe assembly  284 . A C-clip  296  retains the probe assembly  284  within a probe bore  288  of the slide frame  282 . The bushing bore  233  has an annular seat  235  with an inner diameter which is large enough to prevent contact between the probe tip  201  and the slide frame  282  during use. 
     One drawback with slide assembly  228  is that the annular bushing  231  and the breech face  240  must be aligned precisely so the bushing  231  is not recessed within, or protruding from, the breech face  240 . If the bushing  231  is recessed within the breech face after assembly, as shown in exaggerated form in FIG. 11, an edge  237  of the bushing bore  233  can shave material from the rim of a cartridge during loading and/or ejection, gradually accumulating deposits over time which may cause an electrical short circuit. The recession may also cause a “fail to extract” if the cartridge expands rearwardly when fired and is forced, or deformed, into the recession. 
     If the breech face bushing  231  protrudes beyond the breech face  240 , after assembly, as shown in exaggerated form in FIG. 12, a cartridge may catch on a corner  239  during loading, and partially or completely jam in the firing chamber. In summary, achieving an acceptable fit between the breech face  240  and the breech face bushing  231  is a difficult and cumbersome task requiring expensive manufacturing procedures. 
     Referring to FIGS. 13-14, the manufacturing problems discussed above in the area of the breech face are avoided with the slide assembly embodiment designated as numeral  328 . A ceramic breech face insert  341  is press-fitted into a breech face channel  343  of a slide frame  382 , and includes a breech face  340  and a probe tip bore  389  defined on the firing axis  20 . The slide frame  382  has a firing probe bore  388  with an annular seat  390  that receives a firing probe assembly  384  and its steel, uncoated probe tip  301 . A C-clip  396  retains the probe assembly  384  within the probe bore  388 . The probe tip  301  does not require a ceramic coating because it is sized to pass through the annular seat  390  without making contact therewith. The probe tip  301  therefore extends through the ceramic breech face  340  to contact a loaded cartridge without any concern about electrical shorts between the probe tip  301  and slide frame  382 . Because the breech face insert  341  is ceramic, however, attention must be directed to its fit within the breech face channel  343  to avoid cracking during installation and/or normal use. 
     Referring to FIGS. 15-17, a slide assembly  428  combines design features of slide assemblies  228  and  328 , including an annular, ceramic bushing  431  pressed into a steel breech face insert  441 . The insert  441  and bushing  431  are assembled to form a breech face  440  and are then pressed into a breech face channel  443  of a slide frame  482 . A bushing bore  433  is countersunk into a rear face  439  of the insert  441  to form an annular seat  435  on the firing axis  20  which receives and supports a complementary shoulder  447  of the bushing  431 . The bushing  431  defines a probe tip bore  489  which slidably receives a probe tip  401  of a firing probe assembly  484 . A C-clip  496  retains the firing probe assembly  484  against an annular seat  490  of a probe bore  488 . 
     Preferably, the bushing  431  is installed into the breech face insert  441  so that it initially protrudes beyond the bushing  431 , as seen in FIG.  16 . The bushing  431  and insert  441  are then machined, to form a flat breech face  440  as seen in FIG.  17 . 
     Referring to FIGS. 18-19, a slide assembly  528  includes a slide frame  582  with a tip assembly bore configured to receive an annular breech bushing  531 , a compression ring  551 , a bushing retainer  553  and a firing probe assembly  584 . A C-clip  596  retains the firing probe assembly  584  against an annular seat  590  of a firing probe bore  588 . The breech bushing  531  and bushing retainer  553  each define a bore aligned on the firing axis  20  to slidably receive a firing probe tip  501  of the firing probe assembly  584 . 
     The tip assembly bore is divided into three concentrically-aligned sections: a threaded first section  591  and cylindrical first and second sections  593 ,  595 . The second section  593  has a larger diameter than the third section, thereby defining an annular seat  597 . The breech bushing  531  has first and second axial sections which, respectively, fit snugly within the first and second bore sections  593 ,  595  and against the seat  597 . The compression ring  551  is sized to fit over the second section of the breech bushing  531  prior to its insertion into the slide frame so as to cushion the bushing  531  against the annular seat  597 . 
     The bushing retainer  553  includes a slot  555  on its rear face adapted for use with a screwdriver to tighten the retainer  553  into the slide frame  582 . The compressive characteristic of the compression ring  551  allows the axial location of the breech bushing  531  to be precisely set with respect to the breech face  540 . That is, when the bushing retainer  553  is threaded into the threaded first section  591  after the breech bushing  531  and compression ring  551  are installed, the bushing retainer  553  forces the breech bushing  531  against the compression ring  551  to align the bushing  531  with the breech face  540 . In this manner, the compression ring  551  pre-loads the threads of the bushing retainer  553  and keeps the assembly from loosening. 
     The bushing retainer  553  is constructed of steel to withstand the recoil forces generated by cartridge firings. The compression ring  551  is made of a resilient material which resists the lubricants and contaminants typically encountered during normal use of a firearm. The breech bushing  531  is constructed of a ceramic material to provide the electrical insulation between the probe tip and the slide frame. 
     Referring to FIGS. 20-21, a ground contact bore  561  is located in slide frame  582  to receive a spring-loaded ground contact  563  biased downwardly by a ground contact spring  565 . The ground contact  563  has an engagement section  567  with a reduced cross-sectional area adapted to be engaged by the firing probe assembly  584  when inserted into its bore  588 . The ground contact bore  561  is perpendicular to the firing probe bore  588  (and partially intersects the same) so that when the ground contact  563  is installed in the ground contact bore  561 , and its engagement section  567  is aligned with the firing probe bore  588 , the firing probe assembly  584  retains the ground contact  563  in the slide frame  582 . The engagement section  567  has an axial length that leaves the contact  563  a slight amount of axial play in its bore  561 . The ground contact bore  561  is located a distance  569  from the rear end of the slide frame  582  so that the ground contact  563  properly engages an associated terminal (discussed below) mounted on the backstrap module  50  when the slide frame  582  is in its firing position. 
     Referring to FIG. 22, the firing probe assembly  584  includes a stainless steel firing probe  602 , a firing probe spring  604 , and a non-conductive probe release pin  606  contained within a molded, two-piece, plastic firing probe housing assembled from the upper and lower housing halves  612 ,  614 . The assembled housing halves define an internal, generally-cylindrical firing probe cavity  616 , a release pin bore  620  through its rear end  622 , and a probe tip bore  624  through its front end  626 . 
     The firing probe  602  includes a probe tip  601  which extends forwardly through the probe tip bore  624 , and a blind bore  629  that receives the firing probe spring  604 . As discussed briefly above, in connection with the camming action produced by a cartridge being loaded in the firing chamber, the probe spring  604  is responsible for pressing the probe tip  601  into electrical engagement with a cartridge loaded in the firing chamber. The relatively light spring force is sufficient to avoid hampering the camming action of the cartridge. The spring  604  also biases the probe release pin  606  rearwardly through the release pin bore  620 . 
     A contact housing  630  defines a countersunk bore  631  which slidably receives a contact plunger  632 , a probe contact  634 , and probe contact spring  636 . The probe contact spring  636  biases the contact plunger  632  upwardly into electrical contact with the firing probe  602 , and the probe contact  634  downwardly into electrical contact with a complementary terminal on the backstrap module (shown below). 
     The contact plunger  632  has a contoured mating surface complementary in shape to the cylindrical outer surface of the firing probe  602 , thereby providing smooth electrical contact between them. The countersink in the bore  631  provides an annular seat  640  which retains the probe contact  634  within the contact housing  630 . 
     To assemble the firing probe assembly  584 , the contact  634 , the contact spring  636  and contact plunger  632  are placed successively into the contact housing  630  and kept in place by the firing probe  602  until the upper housing half  612  is placed over, and sealed to, the lower housing half  613  using adhesive or other known plastic mating process. 
     Referring to FIG. 23, a firing probe assembly  584 ′ includes left and right probe housing halves  612 ′,  614 ′ which enclose the same components described in connection with assembly  584  of FIG.  22 . When assembled, the housing halves  612 ′,  614 ′ define a contact housing  630 ′ which requires a more complex and cumbersome assembly procedure than the procedure required with probe assembly  584 . The probe contact  634 , the probe contact spring  636 , and the probe contact plunger  632  must be held in position while the housing halves  612 ′,  614 ′ are joined together. Hence, the configuration of firing probe assembly  584  is preferred over the configuration of assembly  584 ′. 
     Referring to FIGS. 24-26, the backstrap module  50  is configured to mount and protect the electronic components in pistol  10  and includes a two-piece protective housing  701  with left and right housing halves  703 ,  705  preferably made from injection-molded plastic. The lower dovetails  68  and stops  74  are located on a front side  707  of the housing  701 . The housing  701  has a bottom end  715  configured with a downwardly-facing contact pad  717  which cooperates with the magazine  56  shown in FIG. 2 to conduct electrical power to the backstrap module  50 . 
     Referring to FIG. 27, the contact pad  717  includes three separate electrical terminals  718 ,  719 ,  720  that engage associated contacts on the magazine described in further detail below. Contacts  718 ,  719  are battery terminals, and contact  720  is a terminal which can be linked to a conventional external control module (not shown) for interrogating and/or changing information stored within the backstrap module. It should be understood that the configuration of the contact  720  can be changed to accommodate any appropriate type of external control module. For instance, the contact  720  may be one configured to accommodate the well-known Dallas MicroLAN protocol. 
     Referring to FIGS. 28-29, a circuitboard arrangement  723  is configured for mounting within the housing  701  to organize a majority of the electronic components, and is configured generally to accommodate well known surface mounting and/or post mounting techniques used for arranging electronic components thereon. Selected portions of the circuitboard arrangement  723  are flexible so the entire arrangement can be manipulated into a specific configuration or shape which efficiently utilizes the restricted space within the housing  701 . The flexible portions are not separate components of the arrangement, but merely portions of the circuitboard which are embedded within a flexible rather than rigid material. 
     A rigid main circuitboard section  725  serves as the mounting surface for an array of components collectively referred to as a circuit assembly  726 . The circuit assembly  726  is divided into two collections of components, a security apparatus and a firing apparatus, each of which has distinct and separate functions in the overall operation of the pistol  10 . 
     The security apparatus has the broadly defined function of authorizing the firing apparatus to produce the firing signal. Production of the firing signal is not authorized until the security apparatus receives input signals indicative of compliance with a plurality of operating parameters, including a properly entered personal identification number of firearm operator, a signal indicating the firearm is being held properly, redundant signals from the trigger indicating movement of the trigger to its firing position, and a “Round-in-Chamber” signal indicative of a properly-loaded ammunition cartridge. The Round-in-Chamber is discussed in the co-pending application entitled “A FIREARM HAVING AN INTELLIGENT CONTROLLER”. Once each input signal is received in accordance with the requirements set forth below, circuitry within the security apparatus authorizes the firing apparatus to produce the firing signal and deliver the signal to the firing probe. 
     It should be understood that the security apparatus can be modified to include or exclude any of the operational parameters from the firearm authorizing protocol. Once each required operational parameter is received by the security apparatus, an output signal is produced and transmitted to the firing apparatus which is analogous to a trigger pull in a conventional, percussively detonated firearm. 
     The firing apparatus is adapted to receive either of two signals from the security apparatus, and produce an associated output signal. One type of signal from the security apparatus requires production of a Round-in-Chamber signal which directs the firing apparatus to produce and deliver the appropriate low-voltage signal to the firing probe. The Round-in-Chamber is discussed in the co-pending application entitled “A FIREARM HAVING AN INTELLIGENT CONTROLLER”. The other type of signal from the security apparatus requires the firing apparatus to produce the firing signal. The firing signal is a 150-volt charge produced by a fly-back circuit in the firing apparatus which amplifies energy from the 3-volt battery mounted in the magazine. The firing signal is transmitted to the primer  106  of the cartridge  102  via the probe contact  634  and the firing probe  602 . 
     A first flexible portion  727  extends between the main circuitboard section  725  and a first mountboard  731 . A second flexible portion  733  extends between the main circuitboard section  725  and a keypad  735  (the back side of the keypad is shown in FIG.  26 ). A third flexible portion  737  extends between the keypad  735  and a liquid crystal display (LCD) mountboard  741 . A fourth flexible portion  743  extends between the LCD mountboard  741  and a microswitch mountboard  745 . 
     Referring to FIG. 29, the circuitboard arrangement  723  and its various flexible portions and mountboards are arranged so that certain components can be oriented properly in the backstrap module  50  with respect to the frame, the slide assembly, and/or the user. A magnetic sensor  755 , a high-voltage terminal  757 , and a ground contact terminal  759  are arranged adjacent each other and attached to the first mountboard  731  which faces upwardly and is oriented generally parallel to the firing axis  20  seen in FIGS. 1 and 2. The second flexible portion  733  is shown installed with a curve so that the surfaces of the keypad  735  and main circuitboard section  725  shown in FIG. 27 are in an opposed relationship to each other. When installed, the keypad  735  also assumes a curved shape which conforms with the contour of the backstrap module housing  701  (shown in phantom). As also seen in FIG. 28, the keypad  735  is a component integrated directly into the circuitboard arrangement  723 . In other words, the keypad is actually a portion of the circuitboard arrangement  723  rather than a separate component attached to the circuitboard arrangement  723 . Five manually-actuated, pressure sensitive dome switches  787  are arranged on the side of the keypad  735  facing rearwardly in the assembled pistol  10  so they can be actuated by the user in a manner described below. 
     An LCD  763  is mounted to the LCD mountboard  741 , and faces generally rearwardly so as to be viewed easily by an operator holding the pistol  10  in its sighting position or similar attitude. A microswitch  751  is mounted to the microswitch mountboard  745  and the fourth flexible portion  743  is curved slightly to properly orient the microswitch  751  such that its actuation axis is generally parallel to the first mountboard  731 . As discussed in detail below, this orientation of the microswitch allows it to smoothly interact with movement of the trigger. 
     As seen in FIG. 30, the LCD  763  is secured symmetrically between the left and right module housing halves  703 ,  705 , and is configured to receive information from the processor and communicate that information to the operator in the form of readable symbols or text. Examples of information provided for the user include: whether or not ammunition is loaded in the magazine; whether or not the firearm is in condition to be fired; and whether or not a safety mechanism is activated. Additional information which can be displayed includes the number of ammunition rounds in the magazine, battery condition, whether the firearm has been authorized or is locked, and whether the processor is active or inactive. 
     The ejector  46  has a known configuration that cooperates with the slide frame to eject spent cartridges. Unlike ejectors known in the art, ejector  46  is secured to the backstrap module  50  instead of the frame because the backstrap module comprises portions of the frame which were previously part of the frame. The ejector  46  is pressed generally laterally into engagement with an upper edge  779 , and is secured in place by the left dovetail  62  of the frame  12  when the pistol  10  is assembled. 
     The ground terminal  759  is wrapped over, and is supported by, a terminal rail.  781  of the left module housing half  703 . The ground terminal  759  is configured and positioned to engage the ground contact  563  when the slide assembly  528  is in its firing position. When the slide assembly  528  is moved rearwardly for any reason, electrical continuity is interrupted which prevents a firing signal ever being generated, much less sent to the firing probe. 
     A molded keypad cover  783  is secured within the pistolgrip  58  and includes five input buttons  785 , each of which is configured and positioned to actuate an individual switch  787  of the keypad  735 . The buttons  785  are located in the pistolgrip  58  of the assembled pistol  10  so that each can be depressed by the palm of the typical operator gripping the pistol  10  under normal operating conditions. The keypad cover  783  is manufactured from a soft, resilient material such as Silicon so that comfort of the pistolgrip  58  is not compromised. 
     A transverse mount hole  789  is defined through the module housing halves to receive a hollow mount rivet  791  once the housing halves are assembled. Once the module  50  is assembled and positioned properly on the frame  12 , the pin  81  (shown in FIG. 2) is secured through the hollow mount rivet  791  to securely attach the backstrap module  50  to the pistol frame  12 . 
     Referring to FIGS. 31-32, a backstrap module  50 ′ includes an alternate circuitboard arrangement  723 ′ which is configured slightly differently from circuitboard arrangement  723 . However, the same electronic and mechanical components are used in both modules  50  and  50 ′ as backstrap module  50 . The circuitboard arrangement  723 ′ has a configuration that requires special care so that its flexible portions are not curved sharply to effect conductivity of the circuitboard. A first flexible portion  727 ′ extends between a main circuitboard section  725 ′ and a first mountboard  731 ′, and a second flexible portion  733 ′ extends between the main circuitboard section  725 ′ and a keypad  735 ′. A third flexible portion  737 ′ is configured to connect an LCD mountboard  741 ′ to the keypad  735 ′. The most significant difference in arrangement  723 ′ is its fourth flexible portion  743 ′ connected directly to a top edge  747 ′ of the main portion  725 ′, instead of being connected to the LCD mountboard  741 ′. With this configuration, the fourth flexible portion  743 ′ must be curved sharply (as seen in FIG. 31) to properly orient the microswitch  751  in the module  50 ′. Circuitboard arrangement  723 , which does not present conductivity concerns, is preferred over arrangement  723 ′. 
     Referring to FIGS. 33-35, the backstrap module  50  is configured to mount the magnetic sensor  755  and microswitch  751  so as to be actuated by the trigger bar  918 . The microswitch  751  has an actuation axis indicated by the numeral  802 , which preferably coincides generally with the actuation axis of the trigger bar  918 . When the trigger is pulled or, according to the embodiment contemplated by the present invention, rotated about its pivot point, movement of the trigger is translated into generally axial movement of the trigger bar. The microswitch  751  is then depressed smoothly and efficiently by the trigger bar. The magnetic sensor  755  is positioned behind, above, and to the left of the microswitch  751  by distances, respective, of 0.262 inches, 0.056 inches and 0.131 inches, which are indicated by numerals  804 ,  806  and  808 . 
     The flat trigger bar  918  includes an elongated middle section  810  situated between front and rear trigger bar ends  812 ,  813 . The front end  812  is adapted to be pivotally connected to the trigger  14 , and the rear end  813  is adjusted to actuate the microswitch  751  and magnetic sensor  755 . The rear end  813  includes a rearward-facing blind bore  814  which receives a trigger magnet  816 . The trigger magnet  816  has first and second axial portions  822 ,  824 , the first portion  822  having a diameter larger than the second portion  824 . A cover plate  825  defines a centrally-located aperture  826  having a diameter that is sized between the diameters of the first and second portions of the magnet  816 . The cover plate  825  is placed over the magnet  816  and tack-welded to the trigger bar  918  to retain the magnet  816  securely within the blind bore  814 . 
     Referring to FIG. 36, the trigger magnet  816  produces a magnetic flux  830  which must be carefully controlled to properly and consistently actuate the magnetic sensor  755 . Prior to selecting a magnet for use in the pistol  10 , the location and orientation of the magnetic sensor  755  in the backstrap module  50  was closely approximated. Due to space restraints, the sensor  755  is oriented in the backstrap module with its longitudinal axis (as opposed to its transverse axis) aligned with the actuation axis of the microswitch  751 . As described above, the sensor is offset above, to the left, and behind the microswitch, and the offset distances were factors in selecting an appropriately-sized magnet. Hence, during experiments to study magnet flux and the sensitivity of the magnetic sensor, the only variables were the size of the magnet and the materials used to fabricate the trigger bar and cover plate. 
     Experiments revealed that an optimum magnetic flux  830  was achieved using a trigger bar fabricated from 400 series stainless steel, and a cover plate fabricated from 300 series stainless steel. If either of these materials was used simultaneously to fabricate both the cover plate and trigger bar, the magnetic flux  930  was either over- or under-attenuated. 
     Two sizes of a Neodymium magnet were tested: one with a longitudinal thickness of 0.072 inches; and the other with a longitudinal thickness of 0.087 inches. The 0.087-inch magnet produced a flux density at the sensor of 155 Gauss, which was considered too large, while the 0.072-inch magnet produced a preferred flux magnitude of 135 Gauss at the sensor. Flux from the 0.072-inch magnet could also be measured more consistently than with the 0.087-inch magnet, so the 0.072-inch magnet was selected for use in the preferred embodiment. The magnetic sensor (model AD004 Giant Magnetoresisitve (GMR) Sensor) and the magnet can be purchased from Nonvolatile Electronics, Inc. (NVE), of Eden Prairie, Minn. 
     As seen in FIG. 36, the magnetic flux  830  has an irregular pattern around the magnet  816  when the cover plate  825  and trigger bar  918  are fabricated, respectively, from 300 and 400 series stainless steel. In particular, the magnetic flux  830  extending in the forward direction is kept within the trigger bar  918 , while the magnetic flux  830  extending in the rearward direction is shown passing outside the cover plate  825 . 
     Referring to FIG. 37, the magnet flux  830  is shown graphically as it varies with increased distance from the sensor. Flux levels are indicated on the vertical axis, and the distance of the magnet from the sensor is indicated on the horizontal axis. For example, with a distance of 0.110 inches between the sensor and the magnet  816 , the sensor measures the flux to be approximately 0.13500E-01 (T). During experiments with different magnets, the distance of 0.110 inches was chosen as the point of comparison since that is approximately the distance which corresponds to the position of the magnet where the microswitch is actuated. 
     The magnetic sensor  755  provides the security apparatus with an analog actuation signal when a magnetic flux of a minimum value is detected. In the alternative, a sensor which produces a digital signal can be used in place of the analog sensor. The magnetic sensor is actuated approximately simultaneously as the microswitch. 
     Signals from the magnetic sensor and microswitch are also required by the security apparatus when the user attempts to fire the pistol in rapid succession. Once the magnetic sensor  755  has been actuated by movement of the trigger toward the firing position, the sensor must be reset by recovering the trigger at least to a predetermined “reset” position that requires at least partial trigger recovery. Therefore, successive pistol firings are only possible when the user recovers the trigger to the reset position. The intent is that the security apparatus will not communicate with the firing apparatus until the security apparatus receives the reset signal from the magnetic sensor and the microswitch has been released. It is contemplated that this programming arrangement can be changed according to specific requirements of use, such as by changing the distance that the trigger must be recovered to reset the magnetic sensor. 
     Referring to FIGS. 38-39, a backstrap module  950  is configured to simulate the known double-action cocking and firing mechanisms, and includes an elongated trigger bar  918 , a guide post  954 , a microswitch  951 , and a cam  958 . The cam  958  is generally flat with a rounded front edge  960 , and is anchored horizontally within the housing. The guide post  954  is a round steel bar anchored vertically within the housing proximate the cam  958 . 
     The trigger bar  918  is fabricated from rectangular, 410 series stainless steel bar stock, and includes an elongated body section  970  situated between front and rear ends  962 ,  964 . The front end  962  is configured as on trigger bar  918  shown in FIG. 35, and the rear end has a contoured profile with first and second cam surfaces  966 ,  968  which produces a trigger pull resistance which simulates the force in a conventional double action firing mechanism. 
     The first and second cam surfaces  966 ,  968  have different angles of inclination with respect to the guide post so that when the trigger  14  is pulled by the operator, mechanical feedback is provided to the operator in the form of differing amounts of trigger pull resistance. The first cam surface  966 , having a higher angle of inclination than the second cam surface  968 , produces force on the trigger generally equivalent to the initial trigger resistance in a traditional double-action firing mechanism. As the trigger is pulled further, the second cam surface  968  engages the cam  958 , to provide the operator with a decreased trigger resistance. 
     The trigger bar  918  includes an actuation section  977  which is bent to form a generally horizontal plane and enabling actuation of the microswitch  951  in a generally downward movement. A slot  974  is oriented longitudinally, or generally parallel to the firing axis, to engage the trigger bar  951  on the guide post  954 . The slot  974  is used to maintain proper alignment of the trigger bar  918  in the backstrap module  950  as the cam surfaces  966 ,  968  force downward movement of the trigger bar  918 . 
     Referring to FIGS. 40-41, the magazine  56  has a conventional, elongated metallic housing  978 , a battery  979 , an end cap  980 , a battery retainer  982  and a magazine spring  984 . A conventional follower  985  is disposed within the housing  978  above the magazine spring  984  to move cartridges upwardly in a uniform fashion under force of the magazine spring  984 . 
     The housing  978  is configured for insertion into the pistol frame  12 , as shown in FIG. 2, to store and feed unfired ammunition to the firing chamber, and includes a pair of edges  986  adapted to engage complimentary parallel grooves  987  of the end cap  980 . The magazine spring  984  is inserted underneath the follower  985  to provide the force necessary to urge the stored cartridges toward the firing chamber. The battery retainer  982  is shaped to slide smoothly into the housing after the magazine spring  984  is in place. 
     The battery retainer  982  and the end cap  980  include blind bores  988 ,  989 , respectively, which cooperate to enclose and protect the battery  979 . A lip  990  depends from the underside of the retainer  982  to engage, and prevent removal of, the end cap  980 . 
     An electrical contact pad  991  extends rearwardly from the end cap  980  and includes two spring-steel contacts  993 ,  995  which electrically engage the two downwardly depending terminals  718 ,  719  facing downwardly on the backstrap module bottom end  715 , as shown in FIGS. 24 and 26. When the magazine  56  is inserted into the pistol  10  and locked into position on the pistol frame, the two contacts  993 ,  995  remain in continuous electrical contact with the terminals of the backstrap module  50 . 
     The magazine  56  is assembled by first inserting, successively, the follower  985 , the magazine spring  984  and retainer  982 . The battery is inserted within the blind bore  988  of the retainer  982  and both are pressed upwardly together far enough so that the lip  990  is positioned above the edges  986  of the housing  978 . The end cap  980  is then engaged with, and moved into proper position on, the housing  978 , at which point the retainer and battery are pushed downwardly by the spring  984  until the battery bottoms out in the blind bore  989  of the end cap  980 . 
     The magazine  56  is disassembled by inserting a conventional tool such as a pin wrench through a pin hole  996  defined through the underside of the end cap  980 . The battery and retainer  982  are depressed simultaneously within the housing  978  using the pin wrench until the lip  990  of the retainer  982  will not interfere with removal of the end cap  980 . Generally, it will be sufficient to move the retainer  982  so the lip is above the edge  986  of the housing  978 . At this point, the end cap can be removed from the housing  978 . 
     Now turning to a description of the steps involved in operating the pistol, a loaded cartridge can only be fired after a plurality of input signals are received by the security apparatus. The security apparatus will only authorize the firing apparatus to produce a high-voltage firing signal if each of the inputs is received, including a properly entered authorization code; a “loaded ammunition signal”; a mechanical trigger pull signal; and a magnetic trigger pull signal. In addition, a successive firing will not be authorized until a magnetic reset signal is received by the security apparatus. 
     The security apparatus is programmed with three operational modes: sleep and awake modes, and an authorization mode, or “intent-to-fire” mode. There is no “on/off” switch for the pistol, so it is always in one of the three operational modes. The least active of the modes is the sleep mode, which deactivates the LCD when the pistol is left alone for a predetermined amount of time. This mode is related to a feature known as a “slow grip,” where the security apparatus automatically reverts to the sleep mode from any other mode to save battery power when the pistol has not been handled for a predetermined amount of time. The security apparatus includes logic that recognizes when open or closed circuit, or any of the input switches is actuated, the security apparatus automatically “wakes up” and is prepared to receiver an authorization mode from the operator. Hence, the first method in which the input switches can be used is to wake the pistol from the sleep mode. 
     The input switches are used by the operator to enter an authorization code. The operator enters an authorization code or personal ID number (PIN) by depressing a preselected sequence of switches, similar in fashion to known coded devices. However, when the pistol is initially purchased from a dealership or the factory, the operator must enter a manufacturing code set at the factory which corresponds to the serial number of the pistol frame. Once the operator enters the proper manufacturing code, the security apparatus will then accept entry of his or her own personalized authorization code. It is apparent that the security apparatus can be programmed to allow the operator to change the authorization code if desired. 
     The input switches are to inform the security apparatus when the pistol is being gripped properly and in a manner with an intent to fire the pistol. Experiments have shown that the average user can consistently and simultaneously depress any two of the five input switches. Accordingly, the security apparatus will not authorize firing of the pistol unless at least two of the five input switches remain depressed. 
     Finally, the input switches are used to enter a cancellation code to purposely deactivate the pistol after an authorization code has been entered. Otherwise, the pistol could still be fired, for instance, after being put down for a short time period that is less than a predetermined automatic shut-off time period. To avoid unintentional entering of the cancellation code during use, the magazine must be removed prior to entering the cancellation code. The cancellation code can be changed, however, a representative code is three consecutive actuations of the bottom input switch. 
     The “loaded ammunition signal” is one produced by the security apparatus using a low voltage signal that is passed through a cartridge loaded in the firing chamber. The low-voltage signal travels through the cartridge and electrical resistance is measured and compared to a preselected value. If the round is chambered improperly, such as when jammed or misaligned with the probe tip, the resistance value will be other than optimum, and the loaded ammunition signal will not be satisfied. This signal obviously requires that the slide assembly be in its firing position so that the probe terminal and contact, as well as the ground terminal and contact, are properly engaged. 
     Two inputs are produced when the trigger is pulled: the signal produced by the magnetic sensor and the signal produced by the microswitch. As described above, the trigger magnetically actuates the sensor at a precise position, sending an electronic signal to the security apparatus. Without the trigger feedback signal, the security apparatus will not authorize the firing apparatus to produce a firing signal. Likewise, without the signal from the microswitch by mechanical actuation of the trigger, the security apparatus will not authorize the firing apparatus to produce a firing signal. 
     As mentioned above, the microswitch and magnetic sensor work together to prevent unintentional, successive firings of the firearm. Once the firearm fires a single cartridge, a next cartridge cannot be fired until the trigger has been recovered a distance which resets circuitry within the security apparatus. The recovery distance can be adjusted, but in any event should not be less than a distance corresponding to involuntary and/or unintentional trigger movement during normal trigger actuation during use that results from recoil action of the firearm. 
     It is considered within the scope of the present invention to adapt a circuitboard arrangement similar to the circuitboard arrangement  723  shown in FIGS. 28-29 for use in a firearm that is capable of discharging conventional, percussively-primed cartridges. In such an embodiment, the backstrap module  50  would be in communication with a security apparatus and a linear actuator, such as a solenoid or the like. One such arrangement is shown and disclosed in U.S. Pat. No. 4,793,085, which is hereby incorporated by reference into the present invention in its entirety. 
     In operation, the security apparatus would receives input signals which are indicative of compliance with the operating parameters described above, including entry of the personal authorization number by the firearm operator, gripping the input device sufficiently to actuate the proper arrangement of input switches on the handgrip, as well as actuation of the redundant trigger actuation switches. After the security apparatus registers compliance with the operating parameters, a signal would be supplied to the linear actuator to cause the linear actuator to deliver a blow to the firing pin, thereby detonating the cartridge. 
     It is apparent that other arrangements of components are possible to convert an electronic signal from the security apparatus into mechanical actuation of the firing pin. It is considered within the grasp of a person skilled in the art to adapt the security apparatus and backstrap module of the pistol herein described to a firearm which includes a solenoid or similar device to convert an electrical firing signal into mechanical movement which is sufficient to detonate a conventional percussive cartridge primer. 
     The embodiments of the present invention described in detail above are intended for use in a pistol. However, it should be understood that the principles can readily be applied to a variety of firearms, such as long guns, or other types of devices which utilize a non-impact form of detonating cartridge, such as, a nail gun. While preferred embodiments have been shown and described above, various modifications and substitutions may be made without departing from the spirit and scope of the invention. For example, various other forms of information can be displayed on the display screen for the operator, including an indication of the quantity of cartridges remaining in the magazine. In addition, other materials and methods of constructing the backstrap module and attaching it to the frame are considered within the scope of this invention. 
     Still further, other types of authorization input signals are known in various electronic arts and lend themselves to use in a firearm such as described herein, such as a fingerprint scanning device which recognizes the fingerprint of a person who is authorized to use the firearm. Still even further, it is within the scope of the invention to provide a power source mounted within the backstrap module, thereby obviating the need for several electrical contacts, which may become damaged or corroded during normal use. 
     Accordingly, it is to be understood that the present invention has been described by way of example and not by way of limitation.