Firearm barrels and projectiles

• US 4,176,487 A
• Filed: 02/20/1974
• Issued: 12/04/1979
• Est. Priority Date: 11/18/1970
• Status: Expired due to Term

• Current Assignee: John R. Manis
• Original Assignee: John R. Manis
• Inventors: Manis, John R.
• Primary Examiner(s): Jordan, Charles T.
• Application Number:
  US05/444,008
• Time in Patent Office: 2,113 Days
• Field of Search: 42/76 R, 42/78, 42/1 R, 89/14 R, 89/14 D, 102/92.1, 102/92, 102/92.2, 102/93, 244/3.23
• US Class Current: 42/76.01
• CPC Class Codes: F41A 21/00 Barrels; Gun tubes; Muzzle attachments; Barrel mounting means F41A25/00 takes precedence; barrel attachments for firing grenades or riot-control ammunition from smallarms F41C27/06
• CPC Class Codes: F41A 21/18 Grooves-Rifling
• CPC Class Codes: F42B 10/24 with inclined grooves
• CPC Class Codes: F42B 14/04 Lubrication means in missiles coatings for reducing friction F42B12/82

Abstract

A firearm barrel is provided with a smooth bore which is widened in areas with annular grooves or pockets in the bore walls which act as propellant gas pressure relief areas. When a projectile is fired through the smooth bore, helical notches in the rear of the projectile cooperate with the gas-relief areas of the bore to allow propellant gas to flow and be expanded through the rear helicals, imparting a twist to the projectile, as the cylindric calibre proper of the projectile fills and seals the forward area of the bore proper past the widened bore areas, therefore gas is prevented from escaping past the projectile'"'"'s forward end and the full volume of the gas is retained to propel the projectile forward until it has left the muzzle of the firearm barrel.

Claims

1. In a firearm barrel having a main bore,

at least one gas-relief chamber in a bore wall of said barrel constructed and arranged for imparting a rotational motion to a projectile moving along said barrel, said rotational motion being imparted to the projectile directly by the modulated flow of propellant gases moving past a rearward area of the projectile and expanding into said gas-relief chamber.

2. The firearm barrel set forth in claim 1 wherein said gas-relief chamber walls are unvented therethrough to outside atmosphere.

3. The firearm barrel set forth in claim 1 wherein said bore gas-relief chamber forms a rearward junction point with said bore wall and a forward junction point with said bore wall, and wherein the longitudinal extent between said junctions points is less than the longitudinal extent between zones of the elongated form of a conventional bearing surface proper of a projectile so that the said modulated propellant gases are retained and prevented from substantially passing the forward junction point of said gas-relief chamber by the body of the projectile until the projectile'"'"'s bearing surface of conventional form has moved past said gas-relief chamber'"'"'s forward junction.

4. The firearm barrel set forth in claim 1 wherein said barrel has a smooth bore wall, and said gas-relief chamber forms a rearward junction point with said smooth bore wall and a forward junction point with said smooth bore wall, and wherein the longitudinal extent between said junction points is less than the longitudinal extent between zones of the elongated form of a conventional bearing surface of a calibre proper of a projectile, whereby the said modulated propellant gases are retained and prevented from substantially passing the forward junction point of said gas-relief chamber by the body of the projectile until the projectile'"'"'s bearing surface of conventional form has moved past said gas-relief chamber'"'"'s forward junction.

5. The firearm barrel set forth in claim 1 wherein said gas-relief chamber is formed circumferentially in a zone of said bore wall.

6. The firearm barrel set forth in claim 1 wherein said gas-relief chamber is formed by a laterally widened area of the bore proper, said widened area having sides defining a pocket in one side of the said bore wall.

7. The firearm barrel set forth in claim 6 wherein said bore wall has a plurality of laterally widened areas of the bore proper, each said widened area defining a pocket, each said pocket offset from a preceding one of said pocket.

8. The firearm barrel set forth in claim 3 wherein said bore wall has a plurality of said gas-relief chambers therealong, each spaced a fixed distance ahead of a preceding one of said gas-relief chambers.

9. The firearm barrel set forth in claim 3 wherein said gas-relief chamber is contructed and arranged with said bore wall as to form a standing component of a transient nozzle.

10. A firearm barrel having a smooth bore wall contructed to impart a rotational velocity to a projectile moving therealong directly by the modulated flow of propellant gases within the surface of the projectile comprising:

at least one gas-relief chamber in said smooth bore wall,

said gas-relief chamber defining a widened area of the smooth bore proper,

said gas-relief chamber defining a rearward and forward junction point with said smooth bore wall, said junction points having a longitudinal extent therebetween less than the longitudinal extent of the elongated form of a conventional cylindric bearing surface of the calibre proper of a projectile to which said rotational velocity is to be imparted, so that the full volume of propellant gases are substantially retained until the conventional cylindric bearing surface of the projectile has permanently left the cylindric calibre proper of the said smooth bore wall of said barrel.

11. A firearm barrel with explosive chamber and projectile-seat having a main bore passageway for the movement therethrough of a projectile under force of contained pressure of propellant gases acting on the rear area of the projectile, wherein the improvement comprises:

at least one unvented gas-relief chamber constructed and arranged in a wall of said passageway for momentarily increasing the potential force of said propellant gases acting on the projectile, said gases being subjected to an impulse change of force by the partial sudden relief of said propellant gases under pressure at a projectile into said gas-relief chamber by the transit body of the projectile, thereby the impulse spurt component of motion of propellant gases entering said gas-relief chamber impart an increased transitional velocity to the projectile moving along said passageway under the influence of the modulated flow of said propellant gases,

said gas-relief chamber arranged in offset junction with the wall of said passageway and forming a transiently obturatable opening in said wall,

said opening having a longitudinal extent along said wall less than the longitudinal demension of a conventional bearing surface of the projectile.

12. A firearm barrel having a main bore and projectile-seat, said main bore including at least one gas-expansion chamber in a wall of said main bore, said gas-expansion chamber formed by walls constructed and arranged to have rearward and forward junctions with said main bore wall and forming an offset transiently obturatable opening in said main bore wall, said chamber orientated in the bore wall at a substantial distance forwardly of said projectile-seat, and wherein said gas-expansion chamber wall is unvented to the free outside atmosphere, said chamber wall being constructed and arranged in combination with an area of said main bore wall to form standing components of an enclosed transient nozzle passage.

13. The firearm barrel set forth in claim 12 wherein said enclosed gas-expansion chamber rear junction is formed in combination with a bearing surface area of the main bore construction, said chamber being formed with a wall arranged perpendicular to the transverse dimension of the calibre of said main bore of said barrel.

14. The firearm barrel set forth in claim 12 wherein said enclosed gas-expansion chamber is formed in combination with a bearing surface area of the main bore construction, and said enclosed chamber being formed with a forward wall arranged to slope forwardly to a junction with the constant transverse dimension of the calibre of said main bore of said barrel.

15. The firearm barrel set forth in claim 12 wherein said gas-expansion chamber is constructed and arranged in combination with a bearing surface area with said main bore wall construction to form standing components of an enclosed transient divergent nozzle passage.

16. In a firearm barrel constructed and arranged to accommodate projectiles having base vanes, said barrel having at the rear end area an explosive chamber with an unrifled projectile-seat and having a main bore, an improvement comprising means including gas-relief chambers in a smooth bore wall of said barrel for rotating the projectile having base vanes directly through multiple stages in response to the modulated flow of propellant gases along the base vanes of the projectile, and at and within said gas-relief chambers in a smooth bore wall thereof contiguous to said projectile-seat, said gas-relief chambers defining widened areas of the smooth bore proper, said gas-relief chambers being a substantial distance said firearm barrel from said projectile-seat, said gas-relief chambers characterized by rearward and forward junction points at said smooth bore walls, and having a longitudinal extent therebetween less than the longitudinal extent of the conventional elongated form of the cylindric calibre proper of the bearing surface of a projectile intended for use in said barrel, whereby the full volume of propellant gases in said barrel are substantially retained until the conventional cylindric calibre proper of the bearing surface of the projectile has permanently left the cylindric calibre proper of the said smooth bore walls of said barrel.

17. A firearm barrel having a main bore and projectile-seat, said main bore including at least two laterally disposed gas-relief chambers in the wall of said main bore, said gas-relief chambers formed by walls constructed and arranged to have rearward and forward junctions with said main bore of a calibre proper, one said chamber being formed directly forward of the other adjacent chamber, the proceding chamber being formed with a junction at least at the bore axial point of rearward departure of the other adjacent chamber'"'"'s junction and forming offset transiently obturatable openings in said main bore wall, said chamber orientated in the bore at a substantial distance forwardly of said projectile-seat, and wherein said bore wall and said chamber walls are unvented to the free atmosphere, said chamber walls being constructed and arranged in combination with the bore wall to form standing components of independently enclosed transient nozzle passages,

18. A method of imparting a rotational motion to a projectile in a firearm barrel by flow of propellant gases within the surface of a rear area of the projectile and increasing its forward velocity when fired along the bore in which the projectile acts as an obturator, wherein propellant gases under static pressure in the bore and acting on the rear area of the projectile are subjected to a partial sudden limited relief of static pressure, into a relatively low pressure and temperature captive environment of a pressure relieving expansion chamber opening into the bore wall forwardly of the point of maximum propellant gas pressure, at the instant when the bearing surface of the projectile has initially passed the chamber opening in the bore wall, whereupon the transiently accelerated bore gases are turned by the projectile to which said bore gases give up some of their momentum absorbed from the column of high pressure gases in the bore to thereby effect rotation of the projectile and increase its forward velocity, the gases in said captive environment thereafter turbulently receding rearwardly of the projectile to become a part again of the column of gases in the bore and the residual energy of the gases in said captive environment not absorbed by the projectile or barrel becoming a part of the total energy in the column of gases in the bore, the method including the steps of repeating said partial sudden limited relief of column static pressure into subsequent expansion chambers to thereby recycle said residual energy which, together with the energy in the column of gases, causes transitory increases in projectile rotation and forwarded velocity by converting more of the static pressure of the gases in the column into dynamic pressure at the projectile which thereby absorbs and stores kinetic energy from the column of gases while in the barrel for free flight purposes.