A muzzle accessory for installation on a barrel of a firearm is provided. The muzzle accessory includes an accessory body having a through-channel sized to receive the barrel of the firearm; and a locking member structured to engage the groove of the barrel to lock the muzzle accessory to the barrel.

A muzzle accessory for installation on a barrel of a firearm is provided. The muzzle accessory includes an accessory body having a through-channel sized to receive the barrel of the firearm; and a locking member structured to engage the groove of the barrel to lock the muzzle accessory to the barrel.

A firearm can have a bolt having a plurality of locking lugs that are configured to have a shear area that is larger than that of a standard M16/M4. A bolt carrier can have a bolt that has a double cut cam having an unlocking cam surface that has sufficient dwell increase to delay a start of unlocking when the bolt carrier is used in an M4 carbine. A stepped extractor pin may be provided that prevents disengagement of the extractor pin. A tube can be configured to provide gas from a barrel of the firearm to the piston via the carrier key. The tube can have a heat radiator formed from triangular shaped threads on at least a portion of the tube. A piston on the bolt and can have a plurality of rings including pairs of mating rings that are formed and maintained as a matched pair.

A firearm can have a bolt having a plurality of locking lugs that are configured to have a shear area that is larger than that of a standard M16/M4. A bolt carrier can have a bolt that has a double cut cam having an unlocking cam surface that has sufficient dwell increase to delay a start of unlocking when the bolt carrier is used in an M4 carbine. A stepped extractor pin may be provided that prevents disengagement of the extractor pin. A tube can be configured to provide gas from a barrel of the firearm to the piston via the carrier key. The tube can have a heat radiator formed from triangular shaped threads on at least a portion of the tube. A piston on the bolt and can have a plurality of rings including pairs of mating rings that are formed and maintained as a matched pair.

A rear sight block/barrel assembly for an AK-47 rifle may include a bull barrel and a rear sight block. The bull barrel may include a first portion, a second portion having an outer diameter less than the first portion, and a third portion having an outer diameter less than the second portion. The bull barrel may include a right handed outer diameter threaded portion that extends from the distal end of the bull barrel. The rear sight block may include a body portion including a lower bore configured so the body portion is press fittable onto the second portion of the bull barrel. The body portion may further include a mount portion having a picatinny rail portion and a dovetail portion. The body portion may include a hole for receiving a pin insertable into the hole for securing the gas tube in position relative to the rear sight block.

A visual aid device is provided for an elongate item of equipment intended, in use, to be launched or to launch a projectile at a target region, whereby a user performs an aiming process with the item of equipment by looking along the length thereof from a proximal end to its opposing distal end and directing the distal end in respect of the target region. The visual aid device includes a contrasting region or member located on the item of equipment nearer to the distal end than the proximal end thereof, and being positioned thereon and configured such that it is only fully visible in the peripheral vision of one of the user's eyes during the aiming process.

A visual aid device is provided for an elongate item of equipment intended, in use, to be launched or to launch a projectile at a target region, whereby a user performs an aiming process with the item of equipment by looking along the length thereof from a proximal end to its opposing distal end and directing the distal end in respect of the target region. The visual aid device includes a contrasting region or member located on the item of equipment nearer to the distal end than the proximal end thereof, and being positioned thereon and configured such that it is only fully visible in the peripheral vision of one of the user's eyes during the aiming process.

A reflective sight for use with a firearm includes a rear sight; a light source in the rear sight; a front sight; and a reflector in the front sight, wherein the rear sight and the front sight are aligned using light emitted from the light source that is reflected by the reflector toward the rear sight and through a light path aperture to a user.

A reflective sight for use with a firearm includes a rear sight; a light source in the rear sight; a front sight; and a reflector in the front sight, wherein the rear sight and the front sight are aligned using light emitted from the light source that is reflected by the reflector toward the rear sight and through a light path aperture to a user.

A target sight system includes a base portion with a gun-mounting interface allowing the sight to be firmly fastened to a shooting device. The base also includes a power supply, a target light generator, and a light-passing surface through which the target light passes between the target light generator and a target. The sight system also includes a cover that is detachably removable from the base portion.