Abstract: Primer casing (1) comprising sleeve portion (5) and leading portion (5a), wherein sleeve portion (5) includes tabs (6) to retain primer (11) and blasthole engagement means (2), and wherein leading portion (5a) comprises nose cone (8). Engagement means (2) comprises an array of rigid, multiple projections that are hinged and movable between a retracted position and a blasthole engagement position. Explosive loading hose (13) locales within hose receiving sleeve (7) and can be used to push primer casing (1) into the desired location within the blasthole prior to filling the blasthole with bulk explosive. Methods of loading a blasthole comprising inserting primer (11) into primer casing (1) and positioning primer casing (1) at a desired location in a blasthole are also described and claimed.

Abstract: A segmented explosive device capable of producing a shock wave front upon being exploded by a detonation impulse generated by a selectively operable control device and communicated to the explosive device by a transmission line coupled between the control device and the explosive device. The explosive device has a first charge segment and a second charge segment disposed in an assembled relationship. The first charge segment has a first abutment surface formed on a portion of the exterior thereof and a cavity recessed in the first abutment surface. An output end of the transmission line is received by the cavity and contacts the first charge segment. The cavity of the first charge segment can be configured to dispose explosive material in the path of a plasma zone propagating through voids internal of the explosive device to facilitate advance detonation of the explosive material before a shock wave front trailing the plasma zone reaches the explosive material.

Abstract: A method and apparatus for placement of continuous pre-split, gel explosive in an elongated borehole or cavity. An anchor is attached to one end of a selected length of continuous gel explosive. A suitable anchor is a flexible, plastic “pilgrim's hat” with a hole in the narrow, closed end. The size of the anchor depends on the width of the borehole; the flared skirt should be narrow enough to permit insertion of the anchor into the hole but wide enough to resist removal. One end of the explosive charge is pressed through the hole in the anchor. The remainder of the length of explosive is placed inside a tubular member, such as PVC pipe. The loaded pipe then is inserted into the borehole or cavity with the anchor leading. The pipe is used to push the anchor back into the hole to the desired depth. Then, the pipe is withdrawn. The flexible skirt on the anchor engages the sidewall of the borehole and thus resists removal with the pipe.

Abstract: A detonation transfer subassembly for coupling two detonation activated tools in a work sting such that the work string may be severed between the two detonation activated tools without risk of a detonation. The detonation transfer subassembly comprises first and second explosive carrying members having a detonation transfer member disposed therebetween. The detonation transfer member defines a longitudinal passageway therein. A firing pin is disposed within the longitudinal passageway. The firing pin has a first position proximate the first explosive carrying member and a second position proximate the second explosive carrying member. The firing pin is propellable from the first position to the second position following a detonation within the first explosive carrying member such that the firing pin impacts an explosive disposed within the second explosive carrying member, thereby transferring detonation from the first explosive carrying member to the second explosive carrying member.

Abstract: A device for igniting a solid pyrotechnic charge, including a conducting track, wherein the track consists of a conducting fluid deposited at least partially on the pyrotechnic charge, the pyrotechnic charge is deposited on a solid support and covers an empty cavity of the support, and the cavity forms a empty space between the pyrotechnic charge and the support.

Abstract: Actuator apparatus comprising an actuator including an at least partially hollow housing, a cap element removably mountable on the actuator, and a coil of electrical wire disposed inside the housing, a first portion of the coil being arranged for electrical connection with an electrical connector separate from the actuator and a second portion of the coil being arranged for electrical connection with the cap element, the coil being unwindable outwards from the housing.

Abstract: An electric actuated explosion detonator for use to detonate a confined explosive charge capable of being detonated by heat and/or shock, including an electrical resistor positioned in engagement with the confined explosive charge, the resistor having two electrical contacts and having a predetermined maximum electric current carrying capability and subject to receiving, by the application of an electrical energy source, sufficient voltage and wattage that an instantaneous current flow causes the resistor to instantaneously disintegrate.

Abstract: A smoke-generating projectile has a decomposable effective mass, the mass including a quick-burning deception component for generating spontaneous smoke, and a slow-burning concealment component for generating persistent smoke. The projectile includes an igniter, an ejection charge and/or ignition decomposition charge and at least one ignition delay device. The projectile is constructed so that the energy of decomposition of at least one of the effective mass components is constrained in a radial direction. The ejection charge and/or the ignition decomposition charge, as well as at least one ignition delay device, is installed in the effective mass.

Abstract: A method of stemming a borehole (6) includes the steps of placing a first layer (16) of stemming in the borehole, placing a spherical body (20) in the borehole on top of the layer (16), the body being relatively incompressible and a diameter slightly smaller than the diameter of the borehole, and placing a second layer (18) of stemming in the borehole over the body. The stemming (16, 18) may be placed in the borehole either in direct contact with an explosive (8), or spaced from it by a gas bag (24) or the like form a deck (22). In accordance with an alternate application, the stemming layers (16, 18) may be placed in the borehole prior to placement of an explosive material such that it serves as backfill. Preferably, the stemming includes crushed rock and drill cuttings such as those produced during formation of the borehole. However, other available materials may also be used such as gravel.

Abstract: There is disclosed and claimed a wired network of electrically operable detonators. The network includes a plurality of wired detonator assemblies each including a detonator. The wired assemblies being connected into the network by connectors 10 each including at least one conductive spigot formation 16 removably receivable in a socket 32 which is at least partially lined with a conductive element 34. In the preferred embodiment each connector 10 includes first and second connector halves 12 and 28. The first and second connector halves each includes a body 14, 30 and part of a commercially available connector. The bodies in use forming a water-tight housing for the mating connector parts.

Abstract: An explosive primer designed for use with a fuse cord and an initiating device. The primer consists of a container, which holds the explosive, and a cap received on the open end of the container. The container has two lateral opposing cord tunnels which run the length of the container. The cord tunnels protect the fuse cord on the inside of the primer. The cap has two apertures which align with cord tunnels in the container. The cap has capwell for receiving the detonator. The capwell is pierceable so that a detonator can be inserted through the capwell and embedded directly in the explosive composition inside the container. In addition, the primer contains grooves in the bottom of the container and in the cap. The grooves communicate with the apertures and the recess in the cap and the cord tunnels to create a continuous conduit so that a fuse cord can be threaded therethrough to secure the cord to the primer and selectively position the primer in a borehole at the blast site.

Abstract: A slider (36) has a base fixture (40) and a shielding tube (42). The slider (36) is used to operably couple a detonator (44) to a detonating cord (62) that passes through a booster device (10), i.e., to prevent the detonating cord (62) from directly initiating or fracturing the booster (10). The base fixture (40) includes input lead-retaining means for disposing the input lead (47) of a detonator (44) in signal transfer relation to the detonating cord (62). Optionally, the slider (36) has a detonator retainer (38) for carrying the detonator (44) on the slider (36). Preferably, the detonator retainer (38) is able to hold detonators of various lengths in proper position to initiate the booster device (10). By disposing the shielding tube (42) on the slider (36) a booster device (10) can be used with various detonating cords (62) and a slider (36) having a shielding tube (42) suitable for the chosen detonating cord (62) can be inserted into the booster device (10).

Abstract: A detonator assembly wherein the electrical leads are attached to an electrical connector which maintains the ends of the leads in non-conductive, waterproof condition and which permits the leads to be spliced to another pair of electric leads without any splicing tools. The length of the electrical leads is selected to permit the assembly to be inserted in a booster charge so that the electrical connector is contained entirely within the throughbore in the booster charge. Packaging for such detonator assemblies includes at least one tray integrally formed of fire retardant material. The detonator assemblies fit snugly in parallel elongate recesses in the top of the tray so that when the tray is tipped or inverted the detonators will remain in position. The detonator assemblies are arranged in alternating fashion so that the detonator ends of adjacent assemblies are at opposite sides of the tray.

Abstract: The present invention is directed to an improved connector comprising a first and second holding means for pressure fitting a detonating cord and shock tube in a substantially orthogonal pressure fitting relationship.

Abstract: The invention relates to a shock insensitive explosive train initiating dce including a thin elongated metal casing containing a quantity of hydrated metal picrate therein, a thermite igniter composition disposed adjacent to the hydrated metal picrate charge and an ignition means selected from ignition means consisting of an electric match and a length of fuze cord. In a specific example, the hydrated metal picrate charge is barium picrate hydrate which may be disposed in an open (FIG. 1) or a sealed (FIG. 2) copper or aluminum casing. In the embodiment of FIG. 3, a tin/zinc alloy, protective, safety cover is disposed over a portion of the hydrated metal picrate. This safety cover has a low melting point (200.degree. C.) and is adapted to melt in the event of a fire to thereby "unconfine" the hydrate metal picrate charge prior to it reaching explosion temperature of approximately 341.degree. C.

Abstract: Steps of a process for visualization of a detonation wave involve examini measuring, and confirming a fuel-air explosion by using a ground-based fuel bottle oriented horizontally whereby the explosive dissemination creates a fuel-air cloud with its diameter in the vertical plane and a timed delay, proximate charge explodes within the created cloud. A ground-based high speed camera with a line-of-sight, end-on position with respect to the bottle, photographically records the existence of any occurring detonation wave.

Abstract: An explosive composition of matter comprising nitromethane and picric acid. n a preferred embodiment of the invention commercially available picric acid containing up to 10 percent water by weight is added to the nitromethane up to saturation at room temperature.

Abstract: A blasting agent is disclosed for use in a borehole having a pressure resistant closure. The blasting agent is used in combination with a primary initiating system comprised of a detonator and an initiator for the detonator. The blasting agent is preferably a semi-fluid explosive material having a predetermined sensitivity. The sensitivity is related to the borehole diameter and the initiating system's strength, wherein the blasting agent upon initiation is transformed into explosive products by means of reaction front which consumes substantially all the blasting agent as the reaction front passes through the blasting agent. The reaction front has an average velocity of propagation of between 200 meters/second and 1,000 meters/second for at least 30% of the total length of blasting agent located in the borehole. Another aspect of the invention is a method of blasting wherein the average velocity of propagation of the explosive front in the blasting agent is in a range of between 200 m/sec and 1,000 m/sec.

Abstract: A rapid burning propellant charge for applications including igniters, launch eject motors, and gas generators for automobile air bags. The propellant charge comprises a reticulated substrate having a quantity of interconnected ligaments and a coating of solid propellant material on the ligaments. In order to provide a large amount of surface area for a fast burn time, interstices are between coated ligaments to define propellant surface area for combustion. In applications where minimum smoke is desired, the reticulated substrate is preferably composed of carbon, graphite, or a non-combustible material, and the solid propellant material is preferably a minimum smoke type.

Abstract: A metal detonator housing has a central opening extending therethrough between upper and lower ends and a detonator located in the opening at the lower end. Two leads are conencted to the detonator for causing the detonator to explode upon the application of electrical energy to the two leads. A metal contact spring is located in the opening of the housing at the upper end and extends out of the upper end. The contact spring is electrically insulated from the housing. A spring is located in the opening of the housing and is coupled to the detonator for urging the detonator toward the lower end. One electrical leads extends from the detonator through the central opening of the housing and is electrically connected to the contact spring. The other electrical lead is electrically coupled to the housing.A shunting wire is provided with means for removably attaching one end of the shunting wire to the outside of the housing with the other end of the shunting wire being removably connected to the contact spring.

Abstract: A gas generating type tool includes a propellant charge having an axially extending passage receiving therein an ignition tube containing a quantity of easily ignited, fast burning powder. The propellant and ignition tube are separately handled and/or transported until ready to run into the well. The tube slides easily into the propellant passage. The propellant passage is at least about 12% larger in cross-section than the ignition tube and not more than about 55% larger in cross-section. In circular cross-sections, the propellant passage is at least about 6% greater in diameter and not more than about 25% greater in diameter.

Abstract: A primer for explosives comprises a shaped charge of detonating material for use with an initiator such as a detonator or fuse cord which penetrates into the charge at least about as far as its center of mass, wherein said primer has a cavity for receiving said initiator and a shock attenuator in the form of an insert of inert material of lower density than the detonating material which extends from the surface of the charge into the charge to a desired detonation region and has a portion surrounding at least a part of the length of the cavity and defining an inlet for insertion of said initiating means, the density of the insert relative to the detonating material and shape thereof providing for improved detonation of the primer.

Abstract: A detonator 10 includes an elongate tubular member 12 which defines a longitudinally extending passage 14. A pair of base charges 16 and 20 are located in the passage 14. A primary charge 18 which is substantially disc-shaped is located in the passage 14 and is sandwiched between the base charges 16, 20 such that, upon initiation of the primary charge 18, a shock front generated by the primary charge 18 is propagated by the base charges 16, 20 in a bidirectional manner.

Abstract: An improved plastic film cartridge for flowable explosives is provided. The cartridge comprises a recessed or indented end configuration which recess can be enlarged to provide a locating and retaining pocket for a blasting cap without any penetration of the cartridge film wall. The recess is maintained by means of an internal, elastic cord or strip attached between the sealed ends of the cartridge.

Abstract: An environmental charging and detonation system for submunitions has an arnator in which a firing pin or rotor shaft is used for safing and arming, stab detonation, as well as the rotor for the alternator. A ram air actuated ribbon is deployed during submunition flight for arming the submunition and spinning the rotor of the alternator. The alternator generates energy that is stored in a charging circuit. A multidirection impact detection switch triggers a firing circuit that discharges the energy stored in the charging circuit through an electronic detonator. The electronic detonator will reliably detonate the submunition regardless of the submunition impact angle with a target.

Abstract: A miniaturized delay element was developed for use in medium-and large caliber weapon systems and is realized in a metallic cartridge made of a copper-free light metal. By including a metallic combustible, an oxidant consisting of a halogen-containing high polymer, and metallocenes as sensitizers, an extremely compact and reliable delay element can be produced. By including a detonating charge consisting of an initiating explosive and a metallocene as sensitizer, the delay element can be designed for initiation without darting flame, for striker pins, needles, etc.Due to its properties, the pyrotechnical delay element is particularly well suited for use in highly delayed charges and/or for daughter projectiles and/or for self-destruction of munitions. The delay times achieved can be experimentally and reproducibly determined between 1 and about 30 sec.

Abstract: A novel initiator (blasting cap) for explosives is provided. The initiator, which may be electric or non-electric, comprises a tubular metal shell having within a base charge, a delay train, a priming charge and an ignition means. Interposed between the delay train and the priming charge is an annular collar or ring of resilient material in contact with the inner wall of the metal shell. The construction results in a markedly improved resistance against shock initiation.

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: An explosive primer unit adapted to be initiated instantaneously by low energy detonating cord when the unit comprises an explosive primer and an explosive coupler which operatively joins the low energy detonating cord to the primer.

Abstract: A primer assembly for use in the non-electric initiation of cap-insensitive explosives, especially of deck-loaded explosive charges by means of a single downline of low-energy detonating cord (LEDC), includes a percussion-actuated detonator seated in a cavity in a high-energy primer, and an explosive coupler in which a coupling explosive charge, housed in a plastic connecting block, is in initiating proximity to the detonator's percussion-sensitive ignition charge and sufficiently close to a cord-receiving perforation or conduit in or adjacent the primer as to be initiatable by the detonation of LEDC threaded therethrough. A preferred connecting block has means for engaging the detonator, and means for attaching the block to the primer. Preferably the explosive coupler is seated within a block-like cavity in the primer.

Abstract: A detonator for non-electric detonation systems for blasting charges intended to be initiated by a detonating fuse includes a passage provided in the body of the detonator for passing a detonating fuse through the passage. The detonator includes a conventional percussion cap which is immediately initiated by the detonating fuse for initiating the detonator. Also a booster charge intended for the detonator is provided with a reinforced central channel for the detonating fuse.

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 combination signal transmission tube connector and delay assembly having a housing; means on the housing for engaging at least one signal transmission tube; means on the housing for cutting the transmission tube to expose at least two transmission tube interior portions; a signal delay assembly mounted in the housing for interposition between exposed transmission tube interior portions; and means on the housing for establishing a signal path permitting signal communication between the delay assembly and exposed transmission tube interior portions. The delay assembly preferably has a delay element containing a shaped composition having a preselected combustion time from one side of said element to another side of said element; and at least two transition elements adjacent to the delay element for transferring a signal between the delay element and exposed transmission tube interior portions, each of the transition elements containing a shaped transition composition.

Abstract: A primer assembly for use in the non-electric initiation of cap-insensitive explosives, especially of deck-loaded explosive charges by means of a single downline of low-energy detonating cord (LEDC), includes a percussion-actuated detonator seated in a cavity in a high-energy primer, and an explosive coupler in which a coupling explosive charge, housed in a plastic connecting block, is in initiating proximity to the detonator's percussion-sensitive ignition charge and sufficiently close to a cord-receiving perforation or conduit in or adjacent the primer as to be initiatable by the detonation of LEDC threaded therethrough. A preferred connecting block has a U-shaped channel for engaging the detonator, and a connecting block arm for attaching the block to the primer. Preferably the explosive coupler is seated within a block-like cavity in the primer.

Abstract: The disclosure relates to an explosive charge intended for the explosive jointing of, primarily, large-diameter pipes, such as pipeline pipes. The charge according to the invention is intended to be delivered as a unit ready to be applied immediately on site in the pipe. The only item which is not intended to be included is the detonator which is mounted in place immediately prior to blowing the charge. The charge includes, apart from explosive, also a polymer binder of a more closely defined type and gas blisters preferably in the form of microspheres of glass or plastic and metal or metal oxide powder. The scope of the invention embraces the general configuration of the charge and all components included therein.

Abstract: This invention relates to non-toxic, non-corrosive, lead-free rimfire ammunition.

Abstract: Methods and apparatus are provided for detonating high explosive devices downhole in a well. A high explosive device includes a detonating cord having a first end and a second end. A first device is provided for initiating a detonation of a detonating cord at its first end and a second device is provided for initiating a detonation of the detonating cord at its second end.

Abstract: Detonation apparatus constituting a novel detonation amplifier is disclosed herein having a container enclosing a quantity of combined liquid compositions into which a detonation chamber is submerged. A pyrotechnic charge is suspended with the chamber which is surrounded by the liquid explosive composition. Apertures are provided in the wall of the chamber for permitting the liquid composition to enter the chamber. Activation of the pyrotechnic charge detonates the liquid composition within the chamber which, in turn, detonates the bulk quantity of the liquid composition in the container. In another form, the detonation amplifier includes a shaped charge producing a shock wave reflected back from a baffle to detonate the bulk quantity of the liquid composition in the container.

Abstract: A cylindrical housing for a shock-augmenting charge is provided with axially extending grooves in its outer wall to enhance its radial detonation capability. When used in a cylindrical warhead for augmenting detonation of a main charge of insensitive high explosive, full detonative output is enabled and in addition, a flatter detonation wavefront is generated within the main charge, thereby reducing the need for supplementary waveform shapers.

Abstract: A device for actuating an explosive charge downhole in a wellbore. The device includes a combustive reaction initiator actuated in response to a first pressure condition in a portion of the wellbore and an explosive charge actuator. A time delay device is provided wherein a combustive reaction is initiated by the initiator and continues for a time delay period providing sufficient time for an operator to alter the first pressure condition to a second pressure condition desired at the time of explosive actuation. The delay device is operative at the end of the time delay period after initiation to actuate the explosive charge.

Abstract: A firing mechanism for a tubing conveyed well perforating system used for the completion of formations for both testing and production wherein the primary detonating mechanism of the firing mechanism includes a housing assembly, a capsule assembly retained within the housing assembly having an explosive contained therein adapted to detonate an explosive in the perforating gun of the perforating system, a booster assembly retained within the housing adapted to detonate the explosive in the capsule assembly, and a striker assembly retained by the striker assembly adapted to cause the detonation of the explosive in the booster assembly upon impact therewith.

Abstract: An explosive booster, useful as a starter for one or more low-energy explosive connecting cords, e.g., low-energy detonating cord (LEDC), comprises a detonating explosive charge in the form of a rod having at least one longitudinal perforation for threading one or more (receiver) cords to be initiated by the booster explosive charge, which in turn is initiated by a blasting cap or preferably by the side-output of a (donor) detonating cord in contact therewith. A preferred rod has multiple perforations for threading multiple receiver cords, and is housed within a rigid plastic connector having a portion of its wall circumferentially cut out to allow a donor cord to contact the thereby-exposed rod therein. A trunkline cord is thereby adapted to initiate multiple downlines via a single booster.

Abstract: A primer assembly is provided for use in vertical boreholes wherein the primer charge is initiated by means of electric blasting caps, the electric caps, in turn, being initiated electromagnetically. A covered, cup-shaped primer assembly contains a toroid transformer element and connected electric blasting cap in detonating relationship with a primer explosive charge. The assembly is arranged to receive therethrough a looped wire conductor which conductor passes freely through the toroid transformer. When an energy source is coupled to the looped conductor, a magnetic flux is induced in the toroid transformer which sets off the cap and primer charge. The assembly may be passed freely or slid along the looped conductor to any location in the borehole. The assembly permits the use of electric time-delay, deck-charge blasting without the usual hazards associated with normal electric cap blasting.

Abstract: A cast or pressed explosive primer is provided which is adapted for slidable initiating engagement with a detonating cord. The primer comprises two hermetically sealed shells or cups which are connected together. One shell contains a sensor/signal carrier/delay cap combination and the second shell contains the explosive primer charge. Guides are provided on the outside of the shells for the threading therethrough of a detonating cord. The construction provides protection against the ingress of water or other liquids which may desensitize the initiation system.

Abstract: An end cap for a tubular container having a deep drawn flanged cup adapted to receive an igniter device for igniting the explosive contents of the container, such as the propellant for generating gas for expanding an air bag in a vehicle passenger restraint system. The cup has in its bottom wall, a centrally located aperture normally sealed by a composite laminate of plastic film and metal foil that is rupturable by the signal from the igniter device. A plastic annulus interposed between the igniter device and laminate protects the latter against frictional erosion by rubbing action of the igniter device through environmental vibrations transmitted to the propellant container.

Abstract: A nonelectric detonator device is provided for initiation by a detonator cord, the nonelectric detonator device being securable to a cartridge explosive, an explosive primer charge or one or more outgoing detonator cords, for example, for initiation thereof by the nonelectric detonator device. The detonator device includes an alignment member for securing a detonator cord in initiating relationship thereto. A second alignment member is provided for aligning outgoing detonating cords for initiation by the nonelectric detonator device.

Abstract: An explosive booster is provided for the detonation of insensitive blasting agents. The booster contains TNT as the sole explosive ingredient, is sensitive to blasting cap initiation yet remains insensitive to impact initiation. The booster comprises an elongate structure having a gradually increasing density from end to end, only the less dense end being cap sensitive. Reduced density is accomplished by the incorporation of voids or pockets, by means of, for example, glass microspheres. Particulate sodium nitrate and vermiculite are included as density enhancers.

Abstract: A container for containing a thermosetting explosive charge and delay detonator element is provided. The lower portion of the container has an open bottom and contains the cast explosive charge. A projection and recess are located in that portion of the container which contains the cast explosive charge for retaining the explosive charge within the container and for preventing movement of the charge relative to the container once the charge has solidified. A tubular conduit is longitudinally disposed on the exterior of the container and dimensioned to receive a detonating cord. The container includes an integral alignment structure and housing for the insertion of a delay detonator unit having an initiating element and a delay detonator element adapted so that the initiating element can be positioned adjacent the tubular conduit with the delay detonator element positioned adjacent the cast explosive charge.

Abstract: A chub cartridge has a tubular chamber containing a water-bearing blasting agent, and a longitudinal tunnel adjacent to the tubular chamber and integral therewith. Preferably, the tunnel is full-length and continuous and has holes for threading a detonating cord therethrough and for holding a cord firmly against the tubular chamber for the cord-priming of the cartridges. In primer assemblies, the tunnel also can be used to hold a cap/booster in place, and for lacing cap wires or a low-energy detonating cord. A preferred cartridge is made continuously in a series by wrapping a web of film having a row of holes along one edge so as to form a tube and an outer flap containing the holes, and sealing the tube and the flap so as to form a tunnel containing the holes in its outer portion, the wrapping being performed so that either the inner or outer portion of the tunnel is circumferentially longer than the other.