An improved bolt, bolt carrier and barrel assembly for rifles is described. This invention provides bolt mechanism that has heavier lugs on each side of the extractor to distribute the forces more equally and reliably and thereby reducing firearm failure rate. Moreover, this invention provides a bolt system that is easily adaptable to different ammunition feed devices as well as different ammunition cartridges. This invention further includes a barrel having a barrel extension designed to mate to the symmetrical bolt head lugs of this invention.

A cocking knob and striker assembly for a gas-powered projectile firing device (e.g., a paintball marker). The cocking knob is adapted for operative connection with the striker and has a rearwardly facing spring seat adapted to engage the striker spring. Spring pressure on the cocking knob keeps it engaged with the striker. The arrangement affords easier disassembly and reassembly of the parts.

A method and apparatus for purifying an exhaust gas of an internal combustion engine includes an ammonia generating catalyst for generating ammonia from nitrogen oxides contained in the exhaust gas to be purified, and a nitrogen oxide reducing catalyst downstream of the ammonia generating catalyst, for reduction of nitrogen oxides contained in the exhaust gas to be purified. Generated ammonia is used as the reducing agent. A nitrogen oxide adsorption catalyst is arranged upstream of the ammonia generating catalyst, or the ammonia generating catalyst is arranged in an exhaust pipe branch which pertains to only a part of several separately controllable internal-combustion sources. One or more additional exhaust pipe branches assigned to the other internal-combustion sources and lead to the nitrogen oxide reducing catalyst, while bypassing the ammonia generating catalyst. The part of the internal-combustion sources pertaining to the exhaust pipe branch of which contains the ammonia generating catalyst is operated either continuously or intermittently in a rich mode. Also, one or more combustion sources which feed their exhaust gas to the nitrogen oxide adsorption catalyst may be operated alternately in a lean and rich mode.

Short repeater rifle with a barrel, which has on one of its ends a cartridge receiver; a locking system; a trigger assembly with a trigger and a trigger guard; a firing mechanism; a magazine; and a targeting device, characterized in that the center of gravity of the short repeater rifle lies in front of the trigger guard in the shooting direction.

An assembly for modifying an automatic firearm such as a carbine rifle to relocate operation of the firearm charge handle. The assembly includes a fore-grip bracket, a drive rod movable in the foregrip bracket and attached to the charging handle release lever, and a cocking handle attached to the drive rod, the rod being attached to the charge handle for alternately releasing and latching the charge handle for clearing the firearm. In one embodiment, the foregrip bracket is attached to a removable rail attached to the foregrip by a jaw type device. Another embodiment attaches to the foregrip by attaching the foregrip bracket by screws. Another embodiment attaches to a foregrip having no rail by means of a groove cut in the grip, having a pair of spaced apertures into which hooks of foregrip mount, the bracket being held in place by a rod receiver and rotatable latch.