Ammunition projectile having improved aerodynamic profile and method for manufacturing same
A solid projectile for a firearm having a central cylindrical section defining a bearing surface and an integral, coaxial leading section tapered into a uniform conical surface, the apex at the distal end thereof projecting to a point or apex. The apex angle of the conical surface of the leading section of the projectile is within the range of 20°-40° of arc.
The present invention generally relates to projectiles intended to be fired from firearms, and more particularly to a projectile that includes a specially contoured leading section that is designed to enhance the aerodynamic properties of the projectile and the method of manufacturing the projectile.
2. Description of the Prior ArtThe prior art discloses many attempts to improve the basic design of projectiles intended for use with firearms. With the interest that exists in the field of sport target shooting and with the interest of outdoorsmen, hunters and the like, substantial attention has been given to enhance the external ballistics of the projectile through the design of bullets that yield greater accuracy and range. In addition to accuracy and range, concern has been paid to increasing the velocity of a projectile or a bullet for a given charge. Increasing the velocity of the projectile as well as reducing the drag of the projectile depends very much on the aerodynamic qualities of the projectile itself.
The geometry of a projectile for a firearm is generally divided into symmetrical sections. The body or shank of the projectile is that part of the projectile that comes into full contact with the barrel rifling of the firearm. The cylindrical portion of the projectile is generally referred to as the bearing surface. The prior art generally refers to the term “ogive” to describe the specific point where the leading section of the projectile begins. This is typically where the bearing surface ends and the leading section begins. While the term “ogive” is often used to describe the particular point on the projectile where the leading section reaches the full projectile diameter of the central section of the projectile, the ogive properly refers to the entire curve of the projectile from the distal tip of the projectile to the central section thereof.
As disclosed in the prior art, the ogive of a projectile is usually characterized by the length of its radius. The radius is often given in calibers. The ogive profile of the leading section of a projectile for a firearm is generally described as a tangent ogive design or a secant ogive design. The prior art defines a tangent ogive design as one where the intersection of the central section of the projectile and the radius of the ogive blend together at a tangent point. In a secant ogive design, the point of intersection between the central and leading sections of the projectile is not tangent, the ogive radius being a secant of the arc circle of the ogive.
Irrespective of whether a projectile is categorized as a tangent or a secant ogive design, the distal tip of the ogive is referred to as a meplat. The shape of the meplat has a great effect on external ballistics. The shape of the meplat can also have an effect on terminal ballistics and performance. A representative sample of prior art discloses a projectile that employs an ogive geometry and a relatively short length of the extreme distal tip of the ogive portion of the projectile is further infolded toward the center line of the projectile by a relatively few degrees thereby defining a tapered tip having a void volume in the most distal portion of the open end of the projectile defining a meplat cavity. This configuration can adversely affects the aerodynamic efficiency of the projectile. As the meplat cavity is enlarged, the aerodynamic efficiency of the projectile deteriorates.
The present invention overcomes the disadvantages of the designs disclosed in the prior art by utilizing a leading section of a projectile that comprises ogive segment geometry constituting a secant ogive design adjacent the central section of the projectile and a conical segment extending from the secant ogive segment at the distal end of the projectile. The apex angle of the surface of the conical segment at the distal end of the projectile is within the range of 20°-40° of arc. The use of a leading section comprising a secant ogive design and a conical segment at the distal end will, by definition, require smaller point angles to create a projectile that will be optimized based on the purpose and use of the projectile.
SUMMARY OF THE INVENTIONThe present invention comprises a geometrical configuration for a projectile intended to be used with firearms having a geometrical configuration that improves the aerodynamic efficiency of the projectile and the method for manufacturing the projectile. The projectile comprises a preformed slug or bullet core that can be made of lead but is preferably a lead core in a deformable copper jacket. The projectile comprises a substantially cylindrical central section having an outer bearing surface is adapted to come into full contact of the barrel rifling of the firearm. The cylindrical central section extends forwardly into a leading section that is coaxial with the central section. The leading section comprises a secant ogive segment that intersects with the bearing surface of the central section at an ogive radius that is a secant of the arc circle of the ogive. The secant ogive segment extends into a conical segment at the distal end of the leading section. The surface of the conical segment of the leading section is projected into an apex that is uniformly disposed about the common axis of the central and leading sections of the projectile. The apex angle of the surface of the conical segment is within the range of 20°-40° of arc. The conical segment is approximately 20% of the axial length of the leading section at the distal end of the projectile. The diameter of the meplat at the distal tip of the conical segment of the projectile is uniformly disposed about the common axis of the leading and central sections of the projectile and the area thereof is substantially less than the meplat area of a projectile employing a tangent ogive design for the leading section.
It is an object of the present invention to provide a projectile for a firearm having enhanced external ballistics.
It is another an object of the present invention to provide a projectile for a firearm having improved aerodynamic stability.
It is still another object of the present invention to provide an improved projectile for a firearm that employs a secant ogive design that reduces aerodynamic drag.
It is still yet another object of the present invention to provide a projectile for a firearm that has a meplat of reduced area to enhance aerodynamic properties.
It is still yet another object of the present invention to provide an improved design for a projectile intended for use in a firearm that is inexpensive and easy to fabricate.
The novel features which are believed to be characteristic of the invention, both as to its organization and method of operation, together with further objectives and advantages thereof, will be better understood from the following description considered in connection with the accompanying drawing in which a presently preferred embodiment of the invention is illustrated by way of example. It is to be expressly understood, however, that the drawing is for the purpose of illustration and description only, and is not intended as a definition of the limits of the invention.
The present invention design for the improvement of a projectile for a firearm can be best understood by initial reference to
The term “ogive” is commonly used to describe the specific point where the curving part of the leading section of the projectile begins. The terms “ogive” or “ogive profile” are used to describe the entire leading curve section of a projectile.
Referring to
Contrary to the designs taught by the prior art, a conic segment 46 extends forwardly from base segment 47 of leading section 41. The surface 48 of conic segment 46 projects to apex 49 on longitudinal center line 44. The conic segment 46 is truncated at the distal tip of the ogive to form a meplat 50 that is inwardly folded along the center line to form a conventional meplat cavity (not shown). The apex angle 51 of conic surface 48 is in the range of 20°-40° of arc. To optimize the aerodynamic properties of projectile 40, the axial length of conical segment 46 is approximately 20% of the total axial length of leading section 41.
An understanding of the projectile forming die employed to manufacture the present invention projectile 40 can be best seen by reference to
The conic segment 46 of leading section 41 of the present invention projectile is formed with die piece 80. As can be seen best in
The method by which the present invention projectile can be formed can best understood by reference to
Claims
1. An improved firearm projectile comprising:
- a) a cylindrical central section having an outer surface;
- b) a trailing section in axial alignment with the central section and being integrally formed with the central section and projecting rearwardly therefrom; and
- c) a leading section in axial alignment with the central section comprising an axially aligned ogive base segment and a conic segment, the conic segment being integral with the ogive base segment of the leading section and extending forwardly therefrom, the base segment of the leading section being integral with the central section and extending forwardly therefrom, the conic section having a conical surface defined by an apex angle relative to the axis of the leading section being in the range of 20°-40° of arc.
2. (canceled)
3. An improved firearm projectile as defined claim 1 wherein the axial length of the conic segment is approximately 15-20% of the total axial length of the leading section.
4. (canceled)
5. An improved firearm projectile comprising:
- a) a cylindrical central section having an outer surface;
- b) a trailing section in axial alignment with the central section and being integrally formed with the central section and projecting rearwardly therefrom; and
- c) a leading section in axial alignment with the central section comprising an axially aligned secant ogive base segment and a conic segment, the conic segment being integral with the secant ogive base segment and extending forwardly therefrom, the conic segment having a conical surface defined by an apex angle in the range of 20°-40° of arc relative to the axis of the leading section, the axial length of the conic segment being in the range of 15-20% of the total axial length of the leading section.
6. A method for manufacturing an improved firearm projectile comprising:
- a) providing a die block having an upper cylindrical bore and a lower cylindrical bore in axial communication with one another;
- b) providing a deformable projectile core having a cylindrical central section integral with a curved leading section extending forwardly from the central section;
- c) providing a projectile seating element having an upper axial seating bore adapted to be slidably engaged within the lower cylindrical bore of the die block;
- d) positioning the deformable projectile core within the seating bore of the projectile seating element;
- e) providing a die piece adapted to be slidably engaged within the upper cylindrical bore of the die block, the die piece having an axially aligned conical receiving surface disposed in the lower end thereof;
- f) positioning the die piece within the upper cylindrical bore until the conical receiving surface of the die piece is in engagement with the curved leading section of the deformable projectile core; and
- g) deforming the curved leading section of the projectile core until the upper portion of the leading section of the projectile core into a conic section defining the conical receiving surface of the die piece.
7. An improved firearm projectile manufactured by the method of claim 6.
Type: Application
Filed: Aug 5, 2016
Publication Date: Feb 8, 2018
Inventor: JASON FRIDLUND (Camarillo, CA)
Application Number: 15/330,091