Advanced aerodynamic projectile and method of making same
A projectile is improved aerodynamically by cutting grooves having parabolic transitions between the depth of the groove and the bearing surface. An ejectable tip is attached to the leading edge of the projectile to facilitate greater ballistic coefficient during flight and improved expansion upon impact at a soft target.
1. A projectile comprising:
a projectile body comprising a nose portion, a tail portion, a base, a bearing surface, and a groove cut into the bearing surface, wherein the portion of the projectile between the bearing surface and the groove comprises a curved first transition portion, wherein the curved first transition portion is convex from the bearing surface to the groove relative to a longitudinal axis defined by the center of the nose portion and the center of the base, wherein the curved first transition portion is tangential to the bearing surface, and wherein the curved first transition portion is defined by the von Karman equation.
2. The projectile of claim 1 , wherein the projectile body is manufactured from a material containing at least one of copper, tin, tungsten, aluminum, iron, or gilding metal.
3. The projectile of claim 1 , further comprising:
a hollow meplat having a nose rim surrounding an opening;
a nose wall extending from the nose rim toward the base of the projectile;
a seating channel; and
a tip operable to be seated in the seating channel, the tip comprising a shank, a seating face, a tip nose, and a tip meplat, wherein the tip shank is configured to fit inside the seating channel, and wherein the tip is configured to eject from the hollow meplat after impact with a soft target.
4. The projectile of claim 3 , wherein after impact, the seating face of the tip is configured to transfer force from the impact to the nose rim, and wherein the nose wall is configured to deform sufficiently under the transferred force to disrupt the seating of the tip shank in the seating channel.
5. The projectile of claim 4 , further comprising a fracture groove in the interior of the hollow meplat, wherein the fracture groove is configured to assist fracturing of the nose wall to facilitate expansion of the projectile.
6. The projectile of claim 4 , wherein the tip is aluminum and the projectile body is one of copper or a copper alloy.
7. The projectile of claim 3 , the tip further comprising a beveled transition having a maximum diameter less than the seating surface, wherein the beveled portion reduces from the seating face to the shank, and where in the shank is operable to be seated in the seating channel, and the seating face is operable to be disposed against the nose rim when the shank is seated in the seating channel.
8. The projectile of claim 3 , wherein the tip is manufactured from a material with greater hardness than the material of the projectile body.
9. The projectile of claim 3 , wherein the tip is comprised of a metal having a greater hardness than the material of the projectile body.
10. The projectile of claim 1 , further comprising a curved second transition portion between the bearing surface and the groove.
11. The projectile of claim 10 , wherein the curved second transition portion is defined by the von Karman equation.
12. The projectile of claim 1 , wherein the nose portion has an ogive shape.
13. The projectile of claim 12 , wherein the tail portion has a parabolic cross-section from the bearing surface to the base.
14. The projectile of claim 1 , wherein the nose portion, tip, and base are manufactured with at least a portion of an ogive shape.
15. The projectile of claim 14 , wherein the at least a portion of an ogive shape is defined by the von Karman equation.
16. The projectile of claim 1 , wherein the projectile comprises at least one additional groove cut into the bearing surface, wherein each additional groove has a curved first transition portion and a curved second transition portion.