Enhanced performance ammunition

Abstract

This invention relates to a combination of a gun having a rifled barrel and a round of enhanced performance ammunition, and to a projectile for use in the combination. The invention is especially, but not exclusively related to an improved form of projectile for small arms ammunition. There is provided a projectile with a nominal calibre, for use in a rifled barrel, the projectile comprising: a monolithic body, said monolithic body comprising a. an ogival portion forming the front of the monolithic body; said ogival portion at a point of intersection abuts with b. an elongate cylindrical core, said elongate cylindrical core comprising at least three bands located circumferentially thereon, said bands protruding radially outward therefrom; and said elongate cylindrical core abuts c. a boat tailed portion, forming the rear of the monolithic body, wherein a first band is located at the point where the elongate cylindrical core abuts the boat tail section, wherein a third band is located rearwardly, from the point of intersection, at a distance in the range of from 80% to 120% of said nominal calibre, wherein a second band is located between the first and third bands on said elongate cylindrical core; wherein the monolithic body is formed from a metal having a Vickers Hardness of at least 550 HV, wherein a deformable jacket or coating, surrounds the monolithic body, which defines an outer diameter of said projectile.

Claims

1. A projectile with a nominal calibre, for use in a rifled barrel, the projectile comprising: a monolithic body comprising a metal having a Vickers Hardness of at least 550HV, said monolithic body including a boat tailed portion, forming the rear of the monolithic body, an elongate cylindrical core, said elongate cylindrical core abuts said boat tailed portion and comprises at least three bands located circumferentially thereon, said bands protruding radially outward therefrom, and an ogival portion, said ogival portion at a point of intersection abuts with said elongate cylindrical core, forming the front of the monolithic body, wherein a first band of the at least three bands is located at the point where the elongate cylindrical core abuts the boat tailed portion, wherein a third band of the at least three bands is located rearwardly, from the point of intersection, at a distance in the range of from 80% to 120% of said nominal calibre, wherein the third band is a forward-most band of the at least three bands, and wherein a second band of the at least three bands is located between the first band and the third band on said elongate cylindrical core; and a deformable jacket or coating, surrounding the monolithic body, which defines an outer diameter of said projectile.

2. The projectile according to claim 1, wherein each of said first band, second band, and third band protrudes radially outward from the elongate cylindrical core a height in the range of from 0.5% and 4% of the nominal calibre of the projectile.

3. The projectile according to claim 1, wherein the monolithic body is made from one of steel, tungsten, alloys of tungsten, or tungsten carbide.

4. The projectile according to claim 1, wherein the third band is located at a distance from the point of intersection, in the range of from 85% to 95% of the nominal calibre of the projectile.

5. The projectile according to claim 1, wherein the projectile has a length that extends in a direction from said ogival portion to said boat tailed portion, and each of the first band, second band, and third band has a width, extending is said direction, in the range of from 17% to 23% of the nominal calibre of the projectile.

6. The projectile according to claim 1, wherein the second band is located a distance from the third band in the range of from 17% to 23% of the nominal calibre of the projectile.

7. The projectile according to claim 1, wherein said outer diameter of said projectile is substantially equal to an internal barrel diameter defined by a land of a rifled barrel, and wherein during firing of the projectile the land deforms the deformable jacket or coating into a cavity defined between the third band and the point of intersection.

8. The projectile as claimed in claim 7, wherein upon firing deformation of the deformable jacket or coating provides the projectile with an interference fit with the land so as to provide effective obturation by restricting or preventing the escape of propellant gases past the projectile via the cavity.

9. A combination of a gun having a rifled barrel and a round of ammunition according to claim 1; the barrel comprising rifling grooves which are separated by lands extending helically along a length of the barrel; the outer diameter of the projectile substantially equal to or less than an internal diameter of the barrel defined by the lands, and wherein during firing of the projectile the deformable jacket or coating is deformed by the lands of the barrel into cavities formed between the at least three bands and the point of intersection on the elongate core.

10. The combination according to claim 9, wherein upon firing deformation of the deformable jacket or coating provides the projectile with an interference fit with the lands so as to provide effective obturation by restricting or preventing the escape of propellant gases past the projectile via the rifling grooves.

11. A projectile with a nominal calibre, for use in a rifled barrel, the projectile comprising: a monolithic body including a boat tailed portion, forming the rear of the monolithic body, an elongate cylindrical core that abuts said boat tailed portion and comprises at least three bands located circumferentially thereon, said bands protruding radially outward from said elongate cylindrical core, and an ogival portion that abuts with said elongate cylindrical core at a point of intersection, forming the front of the monolithic body, wherein a first band of the at least three bands is located proximate a location where the elongate cylindrical core abuts the boat tailed portion, wherein a third band is a forward-most band of the at least three bands and is located rearwardly, from the point of intersection, at a distance in the range of from 80% to 120% of said nominal calibre, and wherein a second band of the at least three bands is located between the first band and the third band; and a deformable jacket, surrounding the monolithic body, which defines an outer diameter of said projectile.

12. The projectile according to claim 11, wherein each of said first band, second band, and third band protrudes radially outward from the elongate cylindrical core a height in the range of from 1.5% to 2.5% of the nominal calibre of the projectile, and wherein the projectile has a length that extends in a direction from said ogival portion to said boat tailed portion, and each of the first band, second band, and third band has a width, extending is said direction, in the range of 0.85 mm to 1.15 mm.

13. The projectile according to claim 11, wherein the monolithic body is made from one of steel, tungsten, alloys of tungsten, or tungsten carbide.

14. The projectile according to claim 11, wherein the third band is located at a distance from the point of intersection, in the range of from 80% to 120% of said nominal calibre.

15. The projectile according to claim 11, wherein the second band is located a distance from the third band in the range of 0.85 mm to 1.15 mm.

16. A projectile with a nominal calibre, for use in a rifled barrel, the projectile comprising: a monolithic body including a boat tailed portion, forming the rear of the monolithic body, an elongate cylindrical core that abuts said boat tailed portion and comprises at least three bands located circumferentially thereon, said bands protruding radially outward from said elongate cylindrical core, and an ogival portion that abuts with said elongate cylindrical core at a point of intersection, forming the front of the monolithic body, wherein a first band of the at least three bands is located proximate a location where the elongate cylindrical core abuts the boat tailed portion, wherein a third band is a forward-most band of the at least three bands and is located rearwardly, from the point of intersection, at a distance in the range of from 80% to 120% of said nominal calibre, and wherein a second band of the at least three bands is located between the first band and the third band; and a deformable jacket, surrounding the monolithic body, which defines an outer diameter of said projectile, wherein there are cavities between the jacket and the monolithic body.

17. The projectile according to claim 16, wherein each of said first band, second band, and third band protrudes radially outward from the elongate cylindrical core a height in the range of from 1.5% to 2.5% of the nominal calibre of the projectile, and wherein the projectile has a length that extends in a direction from said ogival portion to said boat tailed portion, and each of the first, second, and third bands has a width, extending is said direction, in the range of 0.85 mm to 1.15 mm.

18. The projectile according to claim 16, wherein the monolithic body is made from one of steel, tungsten, alloys of tungsten, or tungsten carbide.

19. The projectile according to claim 16, wherein the third band is located at a distance from the point of intersection, in the range of from 80% to 120 % of said nominal calibre, and the second band is located a distance from the third band in the range of 0.85 mm to 1.15 mm.

20. The projectile according to claim 16, wherein the cavities include a first cavity between the point of intersection and the third band, and a second cavity between the second and third bands, and wherein during firing of the projectile, barrel rifling deforms the deformable jacket into at least one of the first and second cavities.

Description

(1) The invention will now be described by way of example only with reference to the accompanying drawings, of which:—

(2) FIG. 1 shows a diagrammatic representation of a monolithic body incorporating at least three bands; and

(3) FIGS. 2 and 2a show the projectile shown in FIG. 1, with a jacket thereon

(4) FIG. 3 shows, in section, the monolithic body and part of the cartridge case located in the chamber of a gun having a rifled barrel and ready for firing.

(5) As shown in FIG. 1, a small arms monolithic body 1 comprising an elongate cylindrical core 3, an ogival portion 2, and a rearwardly located boat tailed portion 4.

(6) Along the length of the elongate cylindrical core 3, are located at least three bands (5a, 5b and 5c), between which are created grooves 8.

(7) The ogival portion 2 abuts the elongate cylindrical core 3, at the point of intersection 11. The point of intersection 11 is the point where the elongate cylindrical core has substantially parallel sides. The third band 5c, is located rearwardly, from the point of intersection 11, at a distance 9 in the range of from 80% to 120% of said nominal calibre. The distance 9 is nominally taken from the leading edge 10 to the point of intersection 11.

(8) The boat tail section 4 abuts the elongate cylindrical core 3, at the rear edge 12 of the first band 5a.

(9) The second band 5b is located between the first band 5a and third band 5c. The gap 7 between the first band 5a and second band 5b, is preferably less than the gap between the second band 5b and the third band 5c, more preferably the gap 7 is substantially the same as one width of a band 6.

(10) The bands are preferably all the same width 6, and protrude radially outwards a height 13. Preferably the at least three bands are uniform in their width and height.

(11) The monolithic body 1 is of elongate form and may preferably be cold formed from steel having a Vickers Hardness of at least 550, more preferably 570 HV. It can subsequently be given a heat treatment to provide the desired hardness or other physical properties.

(12) Because of the substantial hardness of the monolithic body material, the projectile is highly effective at penetration of targets such as titanium/kevlar body armour. Moreover, the hardness also serves to minimise ablation of the projectile tip profile, thus further contributing to its effectiveness in target penetration.

(13) FIG. 2 show the projectile 20 which comprises the monolithic body 21 (as exemplified in FIG. 1), with a jacket 22, located thereon. The leading edge 125c of the third band 25c (see FIG. 2a) and the point of intersection 29 form two contact points, such that when the jacket is applied it forms a cavity 28c. Further the at least three bands 25a, 25b and 25c, provide grooves 28b and 28c, such that when the jacket 22 is compressed when it impacts on the rifling of the barrel (FIG. 3), the copper jacket 22 deforms into the grooves 28a, 28b and 28c. The jacket 22 has a thickness 24, selected to provide the desired outer diameter for the nominal calibre of the gun form which it is to be fired.

(14) When the monolithic body 21 and deformable jacket 22 passes from the gun chamber into the rifled part of the barrel, by virtue of its outer diameter 26, the jacket 22 is deformed by the lands of a rifled barrel into the corresponding groove air gaps 28a, 28b and 28c corresponding to the at least three band 25a, 25b, 25c and point of intersection 29. The outer diameter 26 of the jacket material 22 should be substantially equal to the diameter of any rifling grooves (not shown).

(15) The presence of the grooves 28a, 28b, 28c facilitates the necessary deformation of the jacket 22, thus enabling the rifle engraving to take place with a substantially reduced axial force. The fact that the jacket material can deform into the grooves contributes considerably to a dramatic reduction in the axial force required for engraving to occur.

(16) Preferably the monolithic body 21, is covered by a jacket, which is extruded over the monolithic body, and creates a cavity 26.

(17) Therefore, despite the hardness of the monolithic body, barrel wear from this factor is minimised.

(18) It will be evident to the skilled addressee that all of these factors reducing the engraving force will also result in reduced barrel wear, higher muzzle velocity, and hence increased lethality and accuracy.

(19) The optimum design parameters for the projectile according to the invention can be determined by those skilled in the art, based on the teaching contained herein.

(20) The invention is particularly but not exclusively applicable to small arms ammunition. In one particular example, the invention has been successfully applied to 5.56 mm gun and ammunition.

(21) As shown in FIG. 3, in use the round of ammunition comprising the assembled primed and filled cartridge case 33, together with a projectile 31 are fired from a gun having a rifled barrel 34, in the conventional manner, i.e. by chambering the round within the gun chamber 35, and arranging for the primer cap (not shown) to be struck by a firing pin.

(22) When the monolithic body 21 and associated jacket 22 passes from the gun chamber into the rifled part of the barrel, by virtue of its greater diameter, the monolithic body becomes engraved by the rifling 37. The diameter of the monolithic body 21 and associated jacket 22 should preferably be substantially equal to or less than the diameter of the rifling grooves 38, while the grooves 32 (which are formed between the bands 25(a-c) and point of intersection, can have substantially the same diameter as the barrel diameter.

(23) The presence of the grooves 32 facilitates the necessary deformation of the jacket 22, thus enabling the engraving to take place with a substantially reduced axial force. The fact that the jacket 22 can deform into the grooves 32 contributes considerably to a dramatic reduction in the axial force required for engraving to occur.

(24) The jacket 22 is of a malleable material which can be copper or a copper alloy and could additionally comprise an outer layer of a low-friction material such as molybdenum disulphide. This jacket 22 is of a thickness greater than the depth of the rifling grooves, and is of a relatively softer material than that of the monolithic body 21, it can also engrave more readily, and thus contribute for this reason also to a reduction in the engraving force required. Because the jacket 22 is thicker than the depth of rifling, engraving can take place entirely within the coating so that the hard metal of the monolithic body 21 is kept substantially out of contact with the material forming the rifling of the gun barrel. Therefore, despite the hardness of the material forming the main part of the monolithic body 21, barrel wear from this factor is minimised.