A machine gun has a barrel, a receiver assembly comprising a cover, a receiver base and a butt; lock frame comprising an extractor and a gas piston; bolt, return mainspring with guiding bar, gas piston tube, flash absorber, trigger mechanism, gunsight, butt sighting appliances, trigger pull and loading case. A barrel is made of a preform produced of steel. The barrel is coated inside and steel comprises the additional chemical elements.

A machine gun has a barrel, a receiver assembly comprising a cover, a receiver base and a butt; lock frame comprising an extractor and a gas piston; bolt, return mainspring with guiding bar, gas piston tube, flash absorber, trigger mechanism, gunsight, butt sighting appliances, trigger pull and loading case. A barrel is made of a preform produced of steel. The barrel is coated inside and steel comprises the additional chemical elements.

A gun barrel that has a proximal chamber end, a distal muzzle end, and an internal bore bounded by a bore wall, the internal bore having a first rifled bore section proximate to the proximal chamber end of the barrel, a second rifled bore section at the distal muzzle end of the barrel, and a reducing section distal to the first rifled bore section and connecting the first rifled bore section and the second rifled bore section, wherein at least one of the first rifled bore section and the second rifled bore section have straight groove rifling.

A gun barrel that has a proximal chamber end, a distal muzzle end, and an internal bore bounded by a bore wall, the internal bore having a first rifled bore section proximate to the proximal chamber end of the barrel, a second rifled bore section at the distal muzzle end of the barrel, and a reducing section distal to the first rifled bore section and connecting the first rifled bore section and the second rifled bore section, wherein at least one of the first rifled bore section and the second rifled bore section have straight groove rifling.

A novel rifling is disclosed, wherein a plurality of arc segments are disposed equally about the bore of a gun barrel, when viewed in cross-section. The surface of each arc segment comprises a bearing surface that imparts a spin on a projectile moving down a length of the gun barrel.

A novel rifling is disclosed, wherein a plurality of arc segments are disposed equally about the bore of a gun barrel, when viewed in cross-section. The surface of each arc segment comprises a bearing surface that imparts a spin on a projectile moving down a length of the gun barrel.

A method of forming a chamber in a barrel blank has the steps of providing an elongated firearm barrel blank defining a bore and having a muzzle end and an opposed breech end, securing the blank in a fixture, determining a first reference location of the bore at a position proximate to the breech end, based on the first reference location, machining a first rough chamber bore at the breech end and along the bore to a selected depth, determining a second reference location of the bore at a position beyond the selected depth, and based on the second reference location, machining a second precision chamber bore. The fixture may be stationary during the steps of determining and machining. The step of determining a first reference location may include probing a surface of the bore and may include probing at least three different positions about the bore.

A method of forming a chamber in a barrel blank has the steps of providing an elongated firearm barrel blank defining a bore and having a muzzle end and an opposed breech end, securing the blank in a fixture, determining a first reference location of the bore at a position proximate to the breech end, based on the first reference location, machining a first rough chamber bore at the breech end and along the bore to a selected depth, determining a second reference location of the bore at a position beyond the selected depth, and based on the second reference location, machining a second precision chamber bore. The fixture may be stationary during the steps of determining and machining. The step of determining a first reference location may include probing a surface of the bore and may include probing at least three different positions about the bore.

A projectile for loading into a rifled barrel includes a casing having a cylindrical body, a forward aerodynamic end, and a free end opposite the aerodynamic end, the cylindrical body of the casing defining an interior cavity extending to and in open communication with the free end. The projectile also has a bullet sized to initially slidably engage the casing along a partial length of the interior cavity through the free end. Upon discharge of propellant, the bullet is forced to slidably engage the casing farther within the cavity, preferably such that an entire length of the bullet is housed within the casing cavity, whereby a circumference of the casing is increased such that the increased circumference of the casing catches barrel rifling of the muzzleloader rifle. This allows a smaller caliber bullet to be used in a fouled barrel, while increasing accuracy of the muzzleloader rifle.

Methods and apparatuses are described herein for producing a rifling in a barrel of a gun. The barrel defines an axis in a longitudinal direction and comprises an inner wall that defines a bore extending in the longitudinal direction. A tool includes a tool head having an outer contour that corresponds to a shape of the rifling to be produced. The tool head consists of an electrically conductive material. The outer contour of the tool head and the inner wall of the barrel define a gap. An electrolyte solution is pumped through the gap while the tool is guided through the bore, and a pulsed electrical voltage is applied to the barrel and the tool. The barrel is the anode and the tool head is the cathode. The tool is moved through the bore and rotated about the longitudinal axis while the pulsed voltage is applied to produce the riflings.