Jacketed projectile and method of manufacturing
Provided is small arms ammunition projectile ( 24 ) and manufacturing method having a core ( 10 ) with a longitudinal core axis, a forward portion ( 18 ), and a rearward end ( 14 ). The core ( 10 ) has a rear portion ( 16 ) with an edge ( 26 ) that may be chamfered or radiused, a first portion ( 28 ) being frustoconical, and a second portion ( 30 ) adjacent the first portion ( 28 ) being substantially cylindrical. The jacket ( 12 ) has a longitudinal axis ( 99 ) and longitudinally extending socket ( 45 ) to receive the rear portion ( 16 ) of the core ( 10 ). The socket ( 45 ) has a socket bottom ( 46 ), a first socket portion ( 50 ) being frustoconical, and a second socket portion ( 52 ) adjacent the first socket portion ( 50 ) being substantially cylindrical. The core ( 10 ) and jacket ( 12 ) are shaped such that when assembled, the frustoconical portion ( 28 ) of the core ( 10 ) is seated in the frustoconical portion ( 50 ) of the socket ( 45 ) of the jacket ( 12 ), respective contact surfaces ( 31, 41 ) of the second portions ( 30, 52 ) of the core ( 10 ) and jacket ( 12 ) mate together with the longitudinal core axis ( 98 ) and longitudinal jacket axis ( 99 ) being coaxial.
1. A small arms ammunition projectile made from a core and a jacket, comprising:
the core having a longitudinal core axis, a forward portion, a rear portion and a rear end, the rear portion having an edge, a first portion adjacent the edge, the first portion being frustoconical, the edge being chamfered to present a second frustoconical surface steeper in angle than the frustoconical first portion, and the rear portion further having a second portion oppositely adjacent the first portion, the second portion being substantially cylindrical; and
the jacket having a longitudinal axis and a socket extending in a direction of the longitudinal axis to receive the rear portion of the core, the socket having a socket bottom, a first socket portion, the first socket portion being frustoconical, and the socket having a second socket portion adjacent the first socket portion, the second socket portion being substantially cylindrical,
wherein the core and jacket are shaped such that when assembled together, the first frustoconical portion of the core is seated in the frustoconical portion of the socket, and respective contact surfaces of the second portions of the core and jacket mate together with the longitudinal core axis of the core and longitudinal axis of the jacket being coaxial.
2. The projectile of claim 1 , wherein the core includes an uncovered portion being the forward portion.
3. The projectile of claim 2 , wherein the rear portion is a rear part of the core, such that the edge is the rearmost part of the core, the first portion is forwardly adjacent the edge, and the second portion is forwardly adjacent the first portion.
4. The projectile of claim 1 , wherein the frustoconical portions of the jacket and core have substantially matching surface angles relative to their respective longitudinal axes.
5. The projectile of claim 4 , wherein the frustoconical portions have surface angles in the range between about 4 degrees and about 6 degrees relative to their respective longitudinal axes, and preferably in the range between about 4.5 degrees and about 5.5 degrees, and even more preferably in the range between about 5.0 degrees and about 5.5 degrees.
6. The projectile of claim 5 , wherein the frustoconical portion have surface angles of about 5.25 degrees relative to their respective longitudinal axes.
7. The projectile of claim 1 , wherein the core is comprised substantially of a material harder than that of the jacket.
8. The projectile of claim 1 , wherein the jacket is comprised substantially of copper or a copper alloy.
9. A method of assembling a small arms ammunition projectile made from a core and a jacket, the steps comprising:
providing the core having a longitudinal core axis, a forward portion, a rear portion and a rear end, the rear portion having an edge, a first portion adjacent the edge, the first portion being frustoconical, the edge being chamfered to present a second frustoconical surface steeper in angle than the frustoconical first portion, and the rear portion further having a second portion oppositely adjacent the first portion, the second portion being substantially cylindrical;
providing the jacket having a longitudinal axis and a socket extending in a direction of the longitudinal axis to receive the rear portion of the core, the socket having a socket bottom, a first socket portion, the first socket portion being frustoconical, and the socket having a second socket portion adjacent the first socket portion, the second socket portion being substantially cylindrical, wherein the core and jacket are shaped such that when assembled together, the first frustoconical portion of the core is seated in the frustoconical portion of the socket, and respective contact surfaces of the second portions of the core and jacket mate together with the longitudinal core axis of the core and longitudinal axis of the jacket being coaxial;
moving the rear portion of the core into the socket leading with the edge and first portion of the core; and
continuing to move the core and jacket together until the rear end of the core seats against the socket bottom of the jacket, and the first portion of the core seats into the first socket portion of the jacket, and the second portion of the core is engaged by the second socket portion of the jacket.
10. The method of claim 9 , further comprising crimping or swaging the core and jacket together.
11. The projectile of claim 1 , wherein the chamfer is at an angle of about 45 degrees relative to the longitudinal axis.
12. The projectile of claim 7 , wherein the core is comprised substantially of at least one of steel and tungsten.