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.

Gun barrels and similar tubular devices for repeatedly guiding fired projectiles are fabricated from superalloys, titanium metals, tantalum metals, and similar metal materials by a flowforming process. Combinations of these metals are also flowformed to produce gun barrels and projectile-guiding tubes. In addition, inner liners for such barrels and tubes are made with these metals and flowforming processes. These barrels and tubular devices can withstand high temperatures and corrosive environments. The flowforming process is efficient and produces strong, yet thin and/or light weight, gun barrels and similar tubular devices.

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 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.