A projectile (10) for firing from a barrel (12) of a firearm has an elongated tubular body (14) with a leading end (16), a trailing end (18) and a passage (100) extending through the body (14) and opening onto the leading end (16). An insert (102) is disposed in the passage (100). A cavity (20) is formed in the body (14) between the insert (102) and the trailing end (18) for holding a volume of propellant. A seal arrangement (22) is formed on the body (14) and located between and in-board of the leading end (16) and the trailing end (18). The seal arrangement (22) extends circumferentially about body to form a substantial seal against an inner circumferential surface of the barrel (12). A driving band (28) is supported on the body (14) between the seal arrangement (22) and the trailing end (18) and arranged to maintain substantial coaxial alignment of the body (14) of the projectile and the barrel (12) of the firearm while the projectile travels along the barrel (12). The driving band (28) has one or more flow paths (38) that enable fluid communication between opposite axial ends of the driving band (28).

A projectile (10) for firing from a barrel (12) of a firearm has an elongated tubular body (14) with a leading end (16), a trailing end (18) and a passage (100) extending through the body (14) and opening onto the leading end (16). An insert (102) is disposed in the passage (100). A cavity (20) is formed in the body (14) between the insert (102) and the trailing end (18) for holding a volume of propellant. A seal arrangement (22) is formed on the body (14) and located between and in-board of the leading end (16) and the trailing end (18). The seal arrangement (22) extends circumferentially about body to form a substantial seal against an inner circumferential surface of the barrel (12). A driving band (28) is supported on the body (14) between the seal arrangement (22) and the trailing end (18) and arranged to maintain substantial coaxial alignment of the body (14) of the projectile and the barrel (12) of the firearm while the projectile travels along the barrel (12). The driving band (28) has one or more flow paths (38) that enable fluid communication between opposite axial ends of the driving band (28).

A projectile for use with a firearm having a rifled barrel can include: a substantially cylindrical projectile body having at a front end an ogival nose section and at a rear end a tail section; a driving band section formed on the projectile body between the nose section and the tail section; a bore rider section formed on the projectile body between the nose section and the tail section; and a driving band lead-off section formed on the projectile body adjacent to the driving band section on a rearward side thereof and having an angled surface, with respect to a horizontal axis of the projectile body, that forms a transition from the driving band section to a portion of the projectile body adjacent to the driving band lead-off section on a rearward side thereof. The driving band lead-off section can be formed having an LD-Haack profile.

A projectile for use with a firearm having a rifled barrel can include: a substantially cylindrical projectile body having at a front end an ogival nose section and at a rear end a tail section; a driving band section formed on the projectile body between the nose section and the tail section; a bore rider section formed on the projectile body between the nose section and the tail section; and a driving band lead-off section formed on the projectile body adjacent to the driving band section on a rearward side thereof and having an angled surface, with respect to a horizontal axis of the projectile body, that forms a transition from the driving band section to a portion of the projectile body adjacent to the driving band lead-off section on a rearward side thereof. The driving band lead-off section can be formed having an LD-Haack profile.

Gun and ammunition solutions which permit the use of High Explosive (HE) rounds and Armor Piercing Fin Stabilized Discarding Sabot (APFSDS) rounds in one weapon. A first system has a gun barrel chamber sized to receive the outer cases of both APFSDS and HE rounds. The chamber has a smooth rear section which abuts a front section having internal helical rifling. A HE round has an outer case with a length that is the same as the length of the smooth rear section of the barrel. A projectile held by the case has a rotating band on a rear end configured to engage the internal helical rifling in the chamber. A second system has a conventional smooth barrel and utilizes a HE round with an outer case having internal rifling in a forward section. A projectile held by the outer case has a circular band mounted to rotate about a rear end thereof to engage the internal rifling.

Gun and ammunition solutions which permit the use of High Explosive (HE) rounds and Armor Piercing Fin Stabilized Discarding Sabot (APFSDS) rounds in one weapon. A first system has a gun barrel chamber sized to receive the outer cases of both APFSDS and HE rounds. The chamber has a smooth rear section which abuts a front section having internal helical rifling. A HE round has an outer case with a length that is the same as the length of the smooth rear section of the barrel. A projectile held by the case has a rotating band on a rear end configured to engage the internal helical rifling in the chamber. A second system has a conventional smooth barrel and utilizes a HE round with an outer case having internal rifling in a forward section. A projectile held by the outer case has a circular band mounted to rotate about a rear end thereof to engage the internal rifling.

A .22 caliber rimfire cartridge includes a generally cylindrical casing having a rearward rimfire end and an opposing mouth end, wherein the rearward rimfire end has an annular rim connecting to a cylindrical casing portion extending to a casing forward edge and a bullet is disposed in the forward mouth end. In embodiments, the bullet comprises copper and a polymer binder. In embodiments, the bullet has a forward tapering portion with a central cavity, a first cylindrical portion with a first diameter and a cylindrical surface directly rearward of the tapering portion, a cylindrical driving band directly rearward of the first cylindrical portion, the cylindrical driving band having a second diameter greater than the first diameter and having an outer second cylindrical surface, a third cylindrical portion directly rearward of the cylindrical driving band, the third cylindrical portion having a third cylindrical surface with a diameter equal to the first diameter. In embodiments, the bullet is positioned with the third cylindrical surface mostly or entirely within the casing. In embodiments, the casing has a circumferential crimp positioned at the third circumferential portion. In embodiments, the third circumferential surface having a circumferential indentation at the circumferential crimp.

The invention includes a non-metal, polymer projectile that can be launched from a launching device having a smooth or rifled bore, wherein the launch is facilitated using combustion, vacuum, air pressure, or hydraulic pressure.

The invention includes a non-metal, polymer projectile that can be launched from a launching device having a smooth or rifled bore, wherein the launch is facilitated using combustion, vacuum, air pressure, or hydraulic pressure.

Launching an aeronautical system can comprise applying force or energy to the system in connection with accelerating the system. Responsive to the force or energy, an element of the system can move along a defined path within the system. The system can comprise a drive that converts motion along the defined path into rotational motion. The drive can rotate a mass within the system, which can be supported by a gas bearing. The rotating mass can comprise the moving element, a different system element, or the entire system. The rotating mass can produce angular momentum and can support gyroscopic stabilization of the aeronautical system. Rotational energy can be selectively imparted to and transferred between system elements in connection with stabilization management. System elements can moderate the system's response to impulsive stimuli associated with rotation and acceleration. A gas bearing can support an external surface of the system during launch.