Abstract: An electrical circuit for electrically dischargeable primers having a conductive body, a first electrical contact area, a bottom plate area, one or more burn out area(s) on the bottom plate area, and a second electrical contact area. The conductive body provides an electrical path between a primer's inside cylindrical wall and an inside surface of the primer's cap or cup. The first electrical contact area makes an electrical contact with the inside surface of the cylindrical wall. The second electrical contact area makes an electrical contact with an inside surface of the primer's cap or cup. The bottom plate area is positioned in a bottom location of an electrically dischargeable primer. At least one, but typically two or more burn out areas are on the bottom plate area. The burn out areas have a reduced cross section area. The total cross section area of the burn out areas must be less than the cross section of any other location on the elongated conductive body.

Abstract: A cartridge assembly 10 includes a shell 12 containing a propellant charge 19. At a rear, open end, the shell 12 holds a force amplifying initiating device 20, in turn holding a rim fire primer 22 in operative association with the propellant 19. A firing pin body 40 is movably held within the device 40 to expose a rear of the body 40 to a shock wave to initiate the device 20. A fore end of the body 40 includes a taper formation 48 having a rounded fore point 50 aligned with an inactive surface of the primer 22 centrally within a firing rim. Inadvertent (mechanical) actuation of the firing pin 40 will fall to cause sufficient and sufficiently fast impingement on the primer to initiate the primer. Only a shock wave can cause initiation. The primer 22 is held in a collar 34 allowing it to flare open upon initiation and holding it within the shell 12 after initiation.

Abstract: A multi-ignition cartridge and associated methods for use with a firearm are provided. The cartridge preferably includes a casing having an interior cavity which at least partially encloses at least one projectile. Chances of misfire and cold fire are substantially reduced by including in the casing a plurality of chambers. Each of the chambers preferably is in fluid communication with the cavity and containing an ignitable substance to ignite a main charge in the casing to propel the projectile from the casing. The ignitable substance in a chamber is ignited by striking a strike plate that can be positioned in contact with the casing. Related methods are provided for propelling the projectile of a firearm by simultaneously increasing pressure in multiple chambers of a cartridge casing so as to ignite in at least one chamber the ignitable substance contained in each so as to ignite a main charge that propels the projectile.

Abstract: A primer assembly includes a head loading assembly including a frontward throughbore, and a rearward throughbore having a stop. A closing plug assembly includes a conically bored open frontward end and an open cylindrical rearward end including an outer flange between the frontward and rearward ends. The closing plug assembly is press fitted into the head loading assembly frontward throughbore. An ignition element assembly is press fitted into the head loading assembly rearward throughbore. The ignition element assembly has an ignition element portion that bears against the stop. The closing plug assembly and the ignition element are located to be captivated by threading a flashtube into a head loading assembly threaded portion.

Abstract: A flashtube liner for a primer assembly including a head loading assembly. A flashtube containing an ignition charge has an open rearward end connected to the head loading assembly. A closing plug assembly includes a conically bored open frontward end and an open cylindrical rearward end that may include an optional outer flange between the frontward and rearward ends. The closing plug assembly is attached to the head loading assembly located rearwardly of the flashtube. A flashtube liner has a flange at an open rearward end. The flashtube liner is inserted into the flashtube to line the inner wall of the flashtube. The flashtube liner is held in place by the flashtube impinging the flashtube liner flange between the head loading assembly or the optional flange, and the open rearward end of the flashtube. The flashtube liner is constructed of an extruded plastic material.

Abstract: A projectile includes a pyrotechnical detonation chain arranged to be ignited in response to a launching of the projectile. The chain includes two successive spaced-apart portions that are spaced apart to prevent ignition from being transferred therebetween. One of the portions is movable into contact with the other. A holder imposes a yieldable retaining force (e.g., friction, or shear pin) against the movable portion. That force can be overcome by momentum of the movable portion when the projectile strikes a target, whereupon the movable portion moves into contact with, and ignites, the other portion.

Abstract: An EFI (exploding foil initiator) or slapper detonator, including a explodable foil (or bridge), a flyer plate and a barrel plate having a movable barrier to close a barrel in a safety mode and for opening the barrel in an arming mode, wherein the movable barrier slides from a closed (safety) position to an open (armed) position under the control of a MEMS (microelectromechanical system) energetic actuator. The slidable barrier is maintained in the closed position by one or more locking devices of the MEMS energetic actuator until predetermined stimuli are detected to cause the locking device(s) to release the slidable barrier, thereby arming the EFI or slapper detonator.

Abstract: An inflator for a vehicle inflatable safety system comprising a housing configured to contain a gas generating material, an igniting assembly, and an activating assembly. The igniting assembly includes an actuator plate that is configured to ignite the gas generating material contained in the housing and backer plate. The backer plate is attached to the housing such that a seal is formed therebetween that is capable of substantially stopping the flow of the gas generated by the gas generating material in any direction other than the predetermined directions. The igniting assembly also comprises a booster cup, an ignition charge, and a percussion primer. The booster cup with a conical-shaped end surface with the percussion primer disposed therein proximate to the actuator plate for igniting the gas generating material. The actuator plate and the end surface of the booster cup are in contact only along the peripheral edges thereof.

Abstract: A caseless propellant charge structure and sensitizer structure for safe ignition and cleaner gas generation. The sensitizer structure is comprised of a sensitizer material which is encapsulated in a protective binder material. The protective binder layer is broken during desired ignition in the combustion chamber. Meanwhile the propellant structure comprises an oxidizer rich layer which also contains fuel and a propellant layer. The oxidizer rich layer is adjacent the sensitizer structure in the strip assembly. The oxidizer rich layer allows ignition while foregoing the need for high concentration of oxidizer throughout the propellant structure thus reducing the mass of solids generated from the oxidizer combustion.

Abstract: A miniaturized bulkhead with a barrier member having a thickness in the range of less than 0.05 inches thick for separating explosive charges on opposites sides. The miniaturized bulkhead is manufactured from an age hardened nickel-base alloy. First and second cavities are separated by the barrier member integral with the initiator body. The first cavity is filled with an explosive donor charge, and the second cavity is filled with an explosive acceptor charge. The composition of the age hardened nickelbase alloy includes nickel in the range of 50-55 percent by weight.

Abstract: This invention relates to a gas generator for a seat belt retracting power generating device to supply power to an emergency retracting device of a seat belt retractor, and aims to reliably ignite an ignition agent and a driving agent by concentrating flames into a small-diameter passage when a primer is ignited, quickly supplying heat to a gas generating agent chamber, and preventing the ignition agent and driving agent within the gas generating agent chamber from being damped.

Abstract: A lead-free percussion primer composition and a percussion cup containing e composition. The lead-free percussion primer composition is comprised of a mixture of about 45 wt % aluminum powder having an outer coating of aluminum oxide and molybdenum trioxide powder or a mixture of about 50 wt % aluminum powder having an outer coating of aluminum oxide and polytetrafluoroethylene powder. The aluminum powder, molybdenum trioxide powder and polytetrafluoroethylene powder has a particle size of 0.1 .mu.m or less, more preferably a particle size of from about 200-500 angstroms.

Abstract: An igniting unit for a propellent charge, including a central perforated flame guiding tube having propellant rods which are oriented in an axial direction arranged on the outer surface thereof. On the inner surface of the flame guiding tube and on the casing surface of the propellant rods, however, not on the end surfaces of the latter, there is provided an igniting coating, and in which the igniting coating which is provided on the inner surface of the flame guiding tube is enhanced by an igniting powder strip which is oriented to extend in an axial direction.

Abstract: A priming system includes a block made of pyrotechnically inert material having on one of its surfaces a cavity placed facing an explosive charge. Structure for allowing percussion of the block is mounted at a receiving surface substantially parallel to a surface where the cavity is located. The priming system can thus be completely devoid of pyrotechnic components.

Abstract: A gas generator for providing gases in which the gas generating propellant is ignited by a multiple charge primer. In one embodiment the primer includes a primer housing which contains a sensitizer and output charge pill which are maintained in spaced relationship. When a firing pin is driven into engagement with the primer, the sensitizer frictionally engages with the output charge pill to cause ignition of at least the output charge pill. This ignition of the output charge pill, directly or indirectly, ignites the propellant to provide gases for a desired function. In this regard, the gas generator is suitable for use in a pretensioner for a seat belt restraint system and in an inflator for expanding an air/safety bag.

Abstract: A primer including a primer head assembly and a hollow tubular one-piece body attached thereto. The outer surface of the body tapers to its smallest diameter at the forward end thereof and also includes a screw driver tip at its forward end to assist in the insertion of the primer into the propellant charge within the cartridge case as the primer is being attached to the cartridge case. The body is a high temperature, high glass high carbon composite thermoplastic material.

Abstract: A warning detonator for use on railway tracks or the like is disclosed. The detonator comprises a tube or cylinder (18) having disposed therein at spaced apart locations a length of elastomer (20) and a first explosive component (24, 25). A second explosive component (21) is located therebetween. The second explosive component (21) is also disposed within a cartridge (19) inside the cylinder (18). In use the cylinder (18) is affixed along a length of railway track in a manner whereby the wheel of a passing train progressively compresses the elastomer from its outer end so as to burst an end face (23) of the cartridge (19) and drive the second explosive component (21) into contact with the first explosive component (24, 25) to cause detonation thereof.

Abstract: A non-electrical detonator including an elongate sleeve with a main charge, an initial charge, a delay composition and a gas chamber therein, a subassembly for firing the delay composition including a percussion cap engageable by a double ended striking pin which can be inserted in either direction within a tube, and a fuse held with an elastic plug to operate the striking pin.

Abstract: An ignition unit is provided with an internal housing defining a chamber in which an ignition charge and an ignition element igniting the charge are accommodated. The housing defining the chamber consists of a cover and a container which are connected to one another along a circumferential groove. A distributor housing is mounted on to the housing forming the chamber, in which distributor housing gas outlet openings are provided which are closed by a cap-shaped cover of the chamber. The V-shaped circumferential groove represents a predetermined breaking or separation position of the chamber, for which reason the cover is separated from the container when the ignition charge is ignited. The cover moves away from the container into a space until it strikes the upper end of the distributor housing. With its movement relative to the distributor housing, the cover releases the gas outlet openings so that the gases and flames can emerge from the ignition unit.

Abstract: A percussion igniter for a pyrotechnical gas generator in a safety belt pretensioner is provided. The gas generator has a housing with a guide opening. An impact transmission member such as a ball or pin is received in the guide opening and has an inner end facing an impact face of a priming cap in said gas generator and an outer end projecting from the guide opening.

Abstract: A method of manufacturing an improved lead-free primed rimfire cartridge for ammunition or industrial powerloads providing a gas source for driving fasteners with power-fastening tools. A lead-free priming mixture is consolidated into an annular cavity of a rimfire casing and dried in the cavity. The primer is secured in the cavity by tamping at least a portion of propellant into the casing against and over the dried primer. The tamping pressure per casing may range from 1,300 psi to 8,800 psi. Any remaining portion of required propellent is added over the tamped compacted propellant layer. The ammunition and powerload casings are then sealed and finished in a conventional manner. A rimfire cartridge for both ammunition and industrial powerload applications manufactured as described above is also provided.

Abstract: The invention relates to an ignition device for the propulsive charge of a telescoped piece of ammunition, including a case (2) that is generally cylindrical in shape in which are housed a pyrotechnic composition (3) and a device (4) for ignition thereof. The case (2) has at least one end wall (6) traversed by several channels (10) which each extend along an axis (A1) that slopes in relation to the centre line (A) of the case (2). This device enables all the propulsive charge of a round of ammunition of the telescoped type to be ignited almost immediately.

Abstract: Low-vulnerability component of explosive ammunition and process for initiating a charge of low-sensitivity composite explosive. The subject of the present invention is a low-vulnerability component of explosive ammunition consisting of a preferably metallic enclosure 1 containing a charge 2 of low-sensitivity composite explosive E and, as initiating relay, a plane wave generator 3 consisting, on the one hand, of a cylindroconical cap 7 made of composite explosive A, the large base surface having a diameter d greater than the critical diameter of the explosive E, the cavity 8 of this cap 7 being filled with a composite explosive B and, on the other hand, of a reinforcer made of composite explosive C, of thickness e greater than 0.1 d, the detonation pressure of the explosive C being higher than that of the explosive E.

Abstract: A delay detonator for detonating an explosive charge includes a tubular member having a closed end and an open end, a primary base charge disposed in the closed end of the tubular member and capable of detonating the explosive charge when ignited, a delay train charge disposed adjacent to the primary base charge for burning in response to an ignition signal to thus ignite the primary base charge, an ignition source disposed in the tubular member near the open end for developing an ignition signal, and a transition element disposed between the delay train charge and the ignition source and responsive to an ignition signal from the ignition source for igniting to achieve a substantially steady state combustion rate to the ignite the delay train charge.

Abstract: A delay fuse for a warhead (1) including at least two charges (3, 8) for sequential detonation disposed inside a casing (2). The delay fuse comprises a screen (6) movable in a longitudinal axial direction inside the casing (2) and under the effect of the first charge detonating, from a starting position to a destination position in which it acts on control means (12) for firing a second charge. The fuse includes a component of compressible material (13) disposed inside the casing between the screen (6) and the control means (12). The invention is applicable to shells, rockets, or missiles.

Abstract: A firing pin initiated primer intended to withstand extreme loading forces, includes a capsule having an opening defined by a continuous, deformable side wall and being deformable by the firing pin impacting upon the capsule at the opposite end thereof, an anvil surrounded the capsule, and having an upper portion with a cross section substantially corresponding to that of the capsule, an unbroken lower suppport surface facing the capsule, at the end opposite to the opening and a sealing surface adjacent to the support surface, at least one radial channel formed in the anvil adjacent the sealing surface and extending from the periphery towards the center and converging into an axial channel defined in the anvil, a compartment defined by the supporting surface and bottom and side walls of the capsule and containing a pyrocharge therein, which has the entire upper surface abutting the unbroken support surface of the anvil, and at least one gap formed longitudinally outside of the capsule allowing for the partial

Abstract: On the inside of a cylindrical envelope, an anvil projects from the base of the envelope and has a flat central member extending parallel to an axial plane of the envelope. Flash-holes are formed in the flat areas of the base on either side of the central member so as to create passages in the vicinity of the axial plane of the cylindrical envelope. The central member has two extensions which have a tapered upper portion and connect to the top of the flat central member, forming a relatively flat end, the lower part of the anvil being connected to the cylindrical envelope, forming an integral part of it.

Abstract: In fuse elements of layered structure with long delay times, misfires, occur, above all, if aggravating secondary conditions prevail (such as, for example, high projectile rotation and/or temperature stresses and shock stresses). The safe progression of the reaction through the element is enhanced by providing that, as seen in the propagation direction of the reaction, the central zone of a charge igniting a delay charge projects into a central region of the delay charge. An additional improvement can be achieved by interposing between the ignition charge and the delay section, one or several relay charges and by making the choice of the charge components so that the discontinuities of the characteristic values (especially of the reaction rate) become more even and thus smaller, or by utilizing an ignition charge having a particularly low reaction rate.

Abstract: In fuse elements of layered structure with long delay times, misfires, occur, above all, if aggravating secondary conditions prevail (such as, for example, high projectile rotation and/or temperature stresses and shock stresses). The safe progression of the reaction through the element is enhanced by providing that, as seen in the propagation direction of the reaction, the central zone of a charge igniting a delay charge projects into a central region of the delay charge. An additional improvement can be achieved by interposing between the ignition charge and the delay section, one or several relay charges and by making the choice of the charge components so that the discontinuities of the characteristic values (especially of the reaction rate) become more even and thus smaller, or by utilizing an ignition charge having a particularly low reaction rate.

Abstract: A combustible bayonet type primer for combustible cannon cartridge cases comprises a primer head assembly adapted to be inserted in a cartridge case, a tubular housing made of a combustible material, an igniter strand axially disposed in said housing, and a confining means for confining one end of the igniter strand so that the initial ignition rate is about 1000 m/s. The ignited strand in turn ignites a black powder charge contained within a cloth bag within the tubular housing. The housing is an unpressurized container for the igniter strand and the black powder charge and is consumed during the burn of the propellant bed along with the igniter strand and the combustible case.

Abstract: A delay detonator for causing actual detonation of a device a predetermined period of time following ignition as required by a wide variety of military and civilian operations. The detonator comprises a conventional primer, an expansion chamber separated by a screen from a first-fire combustion section, a delay column, two successive combustion sections separated by a screen, and a detonator output assembly.

Abstract: An ignition system for a combustible insecticide forming a fumigation device. The ignition system utilizes relative motion to actuate an ignitor which, in turn, ignites the insecticide. In one aspect, the relative motion is used to load a spring which, when released, strikes the ignitor to actuate it.

Abstract: A ring fuze for firearm ammunition comprises a hollow fuze ring, which contains a primer. A functionally reliable ring fuze which can easily be manufactured and can be used without a need for a separate abutment is substantially U-shaped in cross-section and its axially extending inner leg and preferably also its bottom are thicker than its axially extending outer leg.

Abstract: A percussion initiated inflator assembly for an airbag comprises a detonator panel that effects essentially simultaneous ignition of a plurality of gas generators by a shock wave.

Abstract: A projectile and method of making it having a forward end portion which comprises a hollow, metallic nose portion (1) containing a charge (3) adapted to detonate by impact against a target without the use of a fuse. In order to achieve safeguard against initiation when the impact velocity is low the cavity in the nose portion, in a distance from the forwardmost part thereof, is covered by a liner (4) of a softer material than the metal of the nose portion. The liner may be of plastic material.

Abstract: This cartridge includes a tubular casing with a firing pin member fixed within the casing intermediate its ends. A frangible projectile is frictionally and sealingly retained in the front compartment of the casing. A piston is located in the rear compartment and consists of a transverse wall exposed at the rear end of the casing, and of a forwardly-extending sleeve slidable within the rear compartment. A primer cap is located within the piston sleeve and has a transverse deformable wall abutting against a boss rearwardly projecting from the firing pin member. The latter includes passages communicating the rear and front compartments. When a plunger actuated by the firing arm pushes the piston forwardly, the firing boss deforms the primer cap transverse wall and cause detonation of the propellant charge. The propellant gases first move the piston rearwardly to uncover the firing cap housing, whereby the gases are expanded in the rear compartment before reaching behind the projectile in the front compartment.

Abstract: An initiator device for activating air crew escape systems comprising a housing of elongate cylindric configuration defining a central chamber having a propellant gas discharge bore at one end and being open at the other end for receiving and static pressure mounting in the central chamber a pyrotechnic cartridge that is held in mounted position by a separate screw threaded head screw threadedly mounted in the housing open end, with the cartridge including a metallic body defining a compression chamber having at the portion of same that is engaged by the housing head, and having a piston received in the compression chamber that is frangibly secured to the cartridge body; the cartridge body also defines a separate pyrotechnic material receiving chamber that is open to the body compression chamber with a column of suitable pyrotechnic materials, tailored in light of the job to be done by the initiator, being mounted in the pyrotechnic material receiving chamber having a head end and terminating with an initiato

Abstract: Method and apparatus are provided for coupling a temporally short electric power pulse from a thick flat-conductor power cable into a thin flat-conductor slapper detonator circuit. A first planar and generally circular loop is formed from an end portion of the power cable. A second planar and generally circular loop, of similar diameter, is formed from all or part of the slapper detonator circuit. The two loops are placed together, within a ferrite housing that provides a ferrite path that magnetically couples the two loops. Slapper detonator parts may be incorporated within the ferrite housing. The ferrite housing may be made vacuum and water-tight, with the addition of a hermetic ceramic seal, and provided with an enclosure for protecting the power cable and parts related thereto.

Abstract: A nonelectric delay detonator has, in a casing, a secondary charge as well as a delay device. The delay detonator is initiated by an ignition transfer hose extending into the casing. A partition is arranged between a hose end and the delay device. Ignition of the delay device is effected by the hose by impact or heat. An auxiliary charge (e.g. a primer cap) is located on the other side of the partition, this auxiliary charge ignites a delay charge of the delay device. In this way, the delay device burns in a closed system from which gas and pressure cannot escape into the hose. Thereby the scattering width of the delay times of the detonator is reduced.

Abstract: A flying-plate detonator containing a high-density high explosive such as benzotrifuroxan (BTF). The detonator involves the electrical explosion of a thin metal foil which punches out a flyer from a layer overlying the foil, and the flyer striking a high-density explosive pellet of BTF, which is more thermally stable than the conventional detonator using pentaerythritol tetranitrate (PETN).

Abstract: A novel detonator is equipped with an instant-trigger primer element. The detonator can be triggered mechanically and provides rapid ignition of the delay charge. In this manner, misfires are avoided which occur due to the fact that in case of an only slight impact, a spring-loaded firing pin is again pulled out of the detonator even before igniting the delay charge and can render the detonator useless because of pressure relief. The primer element contained in the detonator exhibits an outer casing into which is embedded, in a shape-mating fashion, an inner casing so that the bottoms of both casing are placed in mutual superposition in such a way that a cavity is formed between them, this cavity being furthermore defined by the sidewall of the outer casing. This cavity houses the primer charge which is to contain, besides the usual oxidants and reducing agents, rapidly acting initiating explosives. A directional ignition jet is produced by a special configuration of an ignition duct.

Abstract: An acceleration resistant pyrotechnic delay unit delays the ignition of a warhead subjected to high acceleration on launch and high deceleration on impact. The delay unit includes a delay cup housing a pyrotechnic train. The delay cup has a primer cavity a delay cavity and a detonator cavity. A frusto-conical passage extends between the primer cavity and the delay cavity, with the small diameter end opening into the delay cavity. Primer, delay and detonator components of the pyrotechnic train fill the respective cavities in the delay cup. The various components of the train are well supported on all surfaces to prevent fracture due to high acceleration and deceleration.

Abstract: A rotational projectile having a hollow, metallic nose portion (1) containing a charge adapted to detonate by impact against a target without the use of a fuse, whereby the nose portion, rearwardly of either a detonatable charge (2) or a component of such a charge, contains a second component (3) situated in an axially through-going and forwardly diverging channel (5) in a non-metallic insert (4) in the nose portion (1).

Abstract: A propellant charge for the reduction of base eddying or drag of a shell 12 with a centrally disposed ignition conduit and an ignition device for the charge disposed in the conduit. To improve the ignition readiness of the propellant charge, the inner surface of the propellant charge, which surrounds the ignition conduit, is formed so that it conically narrows in the aft direction. Additionally, the inner surface of the propellant charge may be provided with stepped sections. Finally, the ignition conduits disposed in the housing of the ignition device may be disposed at an angle relative to the longitudinal axis of the propellant charge so that they face the inner surface thereof.

Abstract: A detonator assembly is provided which is usable at high temperatures about 300.degree. C. A detonator body is provided with an internal volume defining an anvil surface. A first acceptor explosive is disposed on the anvil surface. A donor assembly having an ignition element, an explosive material, and a flying plate, are placed in the body effective to accelerate the flying plate to impact the first acceptor explosive on the anvil for detonating the first acceptor explosive. A second acceptor explosive is eccentrically located in detonation relationship with the first acceptor explosive to thereafter effect detonation of a main charge.

Abstract: The present invention relates to a non-primary explosive detonator comprising a hollow tube (1) with a closed end having a chamber containing a secondary explosive base charge (8), an opposite open end provided with or for the insertion of an igniting means (9, 15,16), and an intermediate confinement adjacent said chamber and containing an initiating charge (7), a delay composition (6) optionally being present adjacent said initiating charge.

Abstract: An auxiliary booster is used to relay and amplify the detonation wave from a standard configured bomb. An explosive system is placed in an extended fuse well to interface with the main charge. The auxiliary booster is initiated as a second, sequential event by this conventional booster charge. Energy of the conventional booster is transmitted into the auxiliary booster charge and the combined energy of the two charges is focused on the auxiliary charge's tapered metal liner. This tapered metal liner is driven through an air gap into the end of the fuse well at hypervelocity. The design of the device provides controlled packaging of energy for the generation of vaporific effects resulting in the collision of the metal liner of the auxiliary charge with the metallic end of the fuse well for enhanced detonation of the main charge.

Abstract: Delay detonators can be made to function reliably at reduced distances from a neighboring detonation by increasing the weight of the detonator's priming charge. Detonators containing about 0.26 g or more of lead azide perform reliably 12.7 cm from a detonation in a shock resistance pipe test, and this performance is reflected in high performance in trenching operations. The higher energy output of the heavier primer charge may compensate for a decrease in the base charge's sensitivity as the detonator shell is deformed or collapsed by shock.

Abstract: Shell for firing practice comprised of a master projectile in the form of a conventional shell which has a hole along its entire axis for the purpose of inserting inside a small bore projectile that comprises a sleeve and in whose inside there is concentrically placed in axial continuity, a cartridge positioned on the bottom of the sleeve which has a first explosive charge that is activated by the mortar firing pin, and where said cartridge possesses a wad having at least one hole to allow the expansive wave to be transmitted to a second firing pin which activates a second explosive charge, and means for transmitting the impelling action of said second charge to a carried projectile.

Abstract: A battery pocket for centerfire sporting ammunition, for example a shotgun cartridge, comprises a cap shell containing a quantity of impact-sensitive priming material, an anvil and a cap chamber having one or more flash holes therein, the or each flash hole being closed by a layer of material that is removable upon, and as a result of, impact-ignition of the priming material. The or each layer preferably comprises a particulate material, such as china clay, in a polymeric binder and the provision thereof renders the battery pockets less mass-explosible.