Abstract: A cartridge that generates higher than typical chamber pressures has an enhanced means of primer retention for retaining the primer in the primer recess of the casing. The means may be a lip folded onto a conical surface, a annular groove to receive deformed primer wall portion material upon detonation, a concavity in the rearward facing wall of the primer, a check valve in the flash tube to inhibit propellant gases from reaching the primer recess, or specifically configured primers with a greater length than diameter and with greater wall thicknesses.

Abstract: A system for firing reduced energy cartridges from a modern sporting rifle utilizes a bolt assembly weighing less than a conventional bolt assembly for such rifles and utilizes blow back for cycling the bolt assembly rather than gas operation. A bolt insert in a polymer bolt carrier of the bolt assembly has a projection that fits within a recess on the rear face of reduced energy cartridges. The reduced energy cartridges having a polymer casing, a rimfire power load for propellant, the power load recessed from the rear face of the casing. Tuning the bolt may comprise adjusting the weight of the bolt or the sliding resistance of the bolt assembly in the upper receiver. The bolt may be formed by metal injection molding with a polymer bolt carrier attached thereto.

Abstract: A cartridge with an expanding bullet that has advantageous terminal effects over an extended range. The expanding bullet including a bullet body including a metal jacket extending from a tail portion to a nose portion and surrounding an interior solid core and defining a forward opening and interior cavity. A tip has an exterior surface substantially flush with an exterior surface of the metal jacket. The tip has a main portion forward of the opening and a tip retention portion that at least partially fills the interior cavity. In certain embodiments the tip retention portion includes one or more fluid entry facilitation means such as a fracture regions configured to, upon impact of the bullet with a target, fracture or deform to expose one or more fluid pathways into the interior cavity and to a forward facing interior surface for initiating expansion of the expanding bullet.

Abstract: A cartridge that generates higher than typical chamber pressures has an enhanced means of primer retention for retaining the primer in the primer recess of the casing. The means may be a lip folded onto a conical surface, a annular groove to receive deformed primer wall portion material upon detonation, a concavity in the rearward facing wall of the primer, a check valve in the flash tube to inhibit propellant gases from reaching the primer recess, or specifically configured primers with a greater length than diameter and with greater wall thicknesses.

Abstract: A cartridge with an expanding bullet that has advantageous terminal effects over an extended range. The expanding bullet including a bullet body including a metal jacket extending from a tail portion to a nose portion and surrounding an interior solid core and defining a forward opening and interior cavity. A tip has an exterior surface substantially flush with an exterior surface of the metal jacket. The tip has a main portion forward of the opening and a tip retention portion that at least partially fills the interior cavity. In certain embodiments the tip retention portion includes one or more fluid entry facilitation means such as a fracture regions configured to, upon impact of the bullet with a target, fracture or deform to expose one or more fluid pathways into the interior cavity and to a forward facing interior surface for initiating expansion of the expanding bullet.

Abstract: A system for firing reduced energy cartridges from a modern sporting rifle utilizes a bolt assembly weighing less than a conventional bolt assembly for such rifles and utilizes blow back for cycling the bolt assembly rather than gas operation. A bolt insert in a polymer bolt carrier of the bolt assembly has a projection that fits within a recess on the rear face of reduced energy cartridges. The reduced energy cartridges having a polymer casing, a rimfire power load for propellant, the power load recessed from the rear face of the casing. Tuning the bolt may comprise adjusting the weight of the bolt or the sliding resistance of the bolt assembly in the upper receiver. The bolt may be formed by metal injection molding with a polymer bolt carrier attached thereto.

Abstract: A system for firing reduced energy cartridges from a modern sporting rifle utilizes a bolt assembly weighing less than a conventional bolt assembly for such rifles and utilizes blow back for cycling the bolt assembly rather than gas operation. A bolt insert in a polymer bolt carrier of the bolt assembly has a projection that fits within a recess on the rear face of reduced energy cartridges. The reduced energy cartridges having a polymer casing, a rimfire power load for propellant, the power load recessed from the rear face of the casing. Tuning the bolt may comprise adjusting the weight of the bolt or the sliding resistance of the bolt assembly in the upper receiver. The bolt may be formed by metal injection molding with a polymer bolt carrier attached thereto.

Abstract: A cartridge that generates higher than typical chamber pressures has an enhanced means of primer retention for retaining the primer in the primer recess of the casing. The means may be a lip folded onto a conical surface, a annular groove to receive deformed primer wall portion material upon detonation, a concavity in the rearward facing wall of the primer, a check valve in the flash tube to inhibit propellant gases from reaching the primer recess, or specifically configured primers with a greater length than diameter and with greater wall thicknesses.

Abstract: A cartridge that generates higher than typical chamber pressures has an enhanced means of primer retention for retaining the primer in the primer recess of the casing. The means may be a lip folded onto a conical surface, a annular groove to receive deformed primer wall portion material upon detonation, a concavity in the rearward facing wall of the primer, a check valve in the flash tube to inhibit propellant gases from reaching the primer recess, or specifically configured primers with a greater length than diameter and with greater wall thicknesses.

Abstract: A cartridge with an expanding bullet that has advantageous terminal effects over an extended range. The expanding bullet including a bullet body including a metal jacket extending from a tail portion to a nose portion and surrounding an interior solid core and defining a forward opening and interior cavity. A tip has an exterior surface substantially flush with an exterior surface of the metal jacket. The tip has a main portion forward of the opening and a tip retention portion that at least partially fills the interior cavity. In certain embodiments the tip retention portion includes one or more fluid entry facilitation means such as a fracture regions configured to, upon impact of the bullet with a target, fracture or deform to expose one or more fluid pathways into the interior cavity and to a forward facing interior surface for initiating expansion of the expanding bullet.

Abstract: A cartridge with an expanding bullet that has advantageous terminal effects over an extended range. The expanding bullet including a bullet body including a metal jacket extending from a tail portion to a nose portion and surrounding an interior solid core and defining a forward opening and interior cavity. A tip has an exterior surface substantially flush with an exterior surface of the metal jacket. The tip has a main portion forward of the opening and a tip retention portion that at least partially fills the interior cavity. In certain embodiments the tip retention portion includes one or more fluid entry facilitation means such as a fracture regions configured to, upon impact of the bullet with a target, fracture or deform to expose one or more fluid pathways into the interior cavity and to a forward facing interior surface for initiating expansion of the expanding bullet.

Abstract: A system for firing reduced energy cartridges from a modern sporting rifle utilizes a bolt assembly weighing less than a conventional bolt assembly for such rifles and utilizes blow back for cycling the bolt assembly rather than gas operation. A bolt insert in a polymer bolt carrier of the bolt assembly has a projection that fits within a recess on the rear face of reduced energy cartridges. The reduced energy cartridges having a polymer casing, a rimfire power load for propellant, the power load recessed from the rear face of the casing. Tuning the bolt may comprise adjusting the weight of the bolt or the sliding resistance of the bolt assembly in the upper receiver. The bolt may be formed by metal injection molding with a polymer bolt carrier attached thereto.

Abstract: A cartridge with an expanding bullet that has advantageous terminal effects over an extended range. The expanding bullet including a bullet body including a metal jacket extending from a tail portion to a nose portion and surrounding an interior solid core and defining a forward opening and interior cavity. A tip has an exterior surface substantially flush with an exterior surface of the metal jacket. The tip has a main portion forward of the opening and a tip retention portion that at least partially fills the interior cavity. In certain embodiments the tip retention portion includes one or more fluid entry facilitation means such as a fracture regions configured to, upon impact of the bullet with a target, fracture or deform to expose one or more fluid pathways into the interior cavity and to a forward facing interior surface for initiating expansion of the expanding bullet.