Projectile for firearms

Abstract

A projectile for firearms is provided, which is designed as a slender rotation body for ultrasonic velocity, having an approximately cylindrical center part, a tip on the front end and a tail on the rear end which tapers conically toward a projectile base, wherein the projectile is designed such that the circumferential flow remains uniform over the entire trajectory thereof from a front shock wave, through a boundary layer enclosing the projectile body to a rear tail vortex.

Claims

1. A bullet (2) for firearms, which is configured as a slender solid of revolution for supersonic velocities comprising an approximately cylindrical middle part (6) that can be embraced by the neck (4) of a cartridge case (1), at its front end a tip (9) that describes substantially a three-dimensional ogive shape and, at its rear end, a tail (10) that tapers conically toward a bullet bottom (12), wherein the bullet has an inwardly recessed rotationally symmetric bullet bottom (12), which has at its center a spire (11) the tip (11′, 11″) of which extends at least to the rear edge (14) of the bullet bottom (12).

2. The bullet of claim 1, wherein the bullet tip (9) describes a solid of revolution with approximately circular ogive.

3. The bullet of claim 1, wherein the bullet tip (9) is constructed as a solid of revolution similar to an elliptical ogive.

4. The bullet of claim 1, wherein the bullet tip, as a solid of revolution, describes an ogive shape approximating the so-called Newton tip.

5. The bullet of claim 1, with caliber 0.338 (8.6 mm), wherein the radius of its tip rounding (18) is between 4 and 8% of the caliber.

6. The bullet of claim 1, wherein a generating meridian (15) of the recess of the bullet bottom (12) describes, between the tip (11′, 11″) of the spire (11) and the rear edge (14) of the bullet bottom, a shallow curve, the radius of curvature of which decreases close to the spire (11) on the one hand and to the rear edge (14) on the other hand.

7. The bullet of claim 6, wherein the maximum depth of the bullet body outside the spire (11) is between 5 and 15% of the caliber.

Description

BRIEF DESCRIPTION OF THE DRAWING

(1) In the drawings,

(2) FIG. 1 shows a longitudinal section through a chamber with inserted cartridge having a bullet of caliber 0.338 (8.6 mm),

(3) FIG. 2 shows an enlarged view of the bullet according to FIG. 1,

(4) FIG. 3 shows a schematic longitudinal section through the bullet according to FIG. 2,

(5) FIG. 4 shows an enlarged partial section in the region of the rear edge of the bullet bottom according to detail IV of FIG. 3,

(6) FIG. 5 shows a schematic longitudinal section through the bullet according to FIG. 3, but with alternative construction of the bullet bottom,

(7) FIG. 6 shows an enlarged partial section in the region of the rear edge of the bullet bottom according to detail VI of FIG. 5, and

(8) FIG. 7 shows a schematic longitudinal section through the bullet according to FIG. 3 with flow (at Mach 2) around the bullet and tail vortex.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(9) The figures of the drawing show a bullet for firearms, illustrated not to scale but namely in various magnifications, of caliber 0.338 (8.6 mm), also known by the name Lapua Magnum. It is suitable for different applications, including military use, since its target-hitting accuracy is also usable for that purpose.

(10) According to FIG. 1, a cartridge 1 with bullet 2 and associated chamber 3 is illustrated respectively in longitudinal section. A cylindrical middle part 6 of bullet 2 is fastened in a constricted neck part 4 of a cartridge case 5, i.e. bullet 2 is seated ready for firing with central alignment in the interior of chamber 3, in which cartridge case 5 is received and axially fixed. A conical portion 7 adjoins neck part 4 of cartridge case 5 and in turn is adjoined by a cylindrical portion 8 of cartridge case 5 for accommodation of the propellant charge. The primer at the closed tail end of cartridge case 5 and the associated ignition mechanism as well as further parts of the firearm are not illustrated in FIG. 1.

(11) Bullet 2 shown in longitudinal section has a rounded bullet tip 9 at the front end, a cylindrical middle part 6 and a tail 10, which tapers conically toward the end and ends with a bullet bottom 12 recessed around a central spire 11.

(12) FIG. 2 shows an enlarged side view of bullet 2, within the cylindrical middle part 6 of which five guide bands 22 to 26 in total are provided between its upper boundary 20 and its lower boundary 21, which bands are separated from one another with four annular grooves 27 and together, as known, function to guide the bullet linearly in the barrel of the firearm. Otherwise, like reference numerals are used for like components in all figures of the drawing, and so repeated particulars and explanations in this regard are not necessary.

(13) The recess of bullet bottom 12 is shown in a schematic bullet diagram according to FIG. 3, together with circumferential edge 13 of rear edge 14 of bullet bottom 12. Detail IV of FIG. 3 is shown in a further enlargement of the recess of bullet bottom 12 in FIG. 4. Meridian 15, which defines the shape of the rotationally symmetric recess around spire 11 of bullet bottom 12, describes a shallow curve, the radius of curvature of which decreases at both ends, on the one hand toward spire 11 and on the other hand toward rear edge 14. According to FIG. 4, tip 11′ of spire 11 ends approximately at the height of rear edge 14 of bullet bottom 12.

(14) According to FIG. 3, bullet tip 9, which is constructed as a solid of revolution, has an ogive shape, which as a solid of revolution adjoins cylindrical middle part 6 of bullet 2. The contour of this solid of revolution describes a substantially elliptical ogive, wherein its middle portion is preferably constructed as a partial portion of an ellipse. The shown ogive shape is approximately the so-called Newton tip, which is known in itself as a bullet shape, and the qualitative curve profile of which is shown by a dot-dash line 17 in FIG. 5.

(15) Bullet tip 18 of rounded construction, wherein the radius of the tip rounding is equal to 4 to 8% of the caliber. The total tip length is equal to approximately 2.0 to 3.0 times the caliber, or approximately 40 to 60% of the bullet length. The length of the conical tail is equal to approximately 75 to 95% of the caliber. The total length of bullet 2 in turn is approximately 4.5 to 5.5 times the caliber size, and the length of cylindrical middle part 6 is approximately 1.5 to 2.0 times the caliber.

(16) Relative to the central axis of bullet 2, the tail cone angle K is approximately 7 degrees (see FIG. 4).

(17) FIGS. 5 and 6 differ from the otherwise like FIGS. 3 and 4 in terms of the construction of bullet bottom 12. In the variants according to FIGS. 5 and 6, tip 11″ of spire 11 extends beyond rear edge 14 of bullet bottom 12, wherein this may be achieved by variation of the spire length or of the depth of the recess of bullet bottom 12.

(18) FIG. 7 shows the flow around bullet 2, which is traveling approximately at Mach 2 and is illustrated in longitudinal section through its middle plane with streamlines corresponding to incident flow against tip 9 toward tail 10. The streamlines resemble the droplet model known from fluid mechanics and, in the region adjoining tail 10 of bullet 2, form a stable tail vortex 31, which is favored by the recessed shape of bullet bottom 12 and which forms a gentle confluence with the tail-end departing flow at bullet 2. In the transition region around rear edge 14 of bullet bottom 12, this is confirmed clearly by the steady profile of the streamlines and impressively by the droplet shape of the antiparallel vortex flow indicated by arrows 32, 33.