High velocity ammunition system and firearm
A round of high velocity ammunition contained within a modified chamber of a conventional firearm has a cartridge case, a sabot mounted within the forward-end of the case and a carrying projectile matching the caliber of the firearm for engaging rifling in the firearm bore, and a quantity of a propellant charge sufficient to impart a muzzle velocity in excess of 25,000 (ft./sec.) to the projectile. The cartridge case and the projectile cooperate with a rearwardly facing abutment surface of the chamber to confine the sabot which has an forwardly facing bearing surface coaxially surrounding a portion of the projectile and in abutting engagement with the abutment surface. When the round is fired substantially instantaneous dynamic forces generated by the gases of explosion propel the projectile from the chamber into and through the bore while simultaneously comprising the sabot to a fracture point. The fragmented sabot is entrained in the gases of explosion and escapes from the firearm through the muzzle end of the barrel.
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This application is entitled to the benefit of and incorporates by reference essential subject matter disclosed in U.S. Provisional Patent Application No. 60/574,246, filed May 25, 2004.
FIELD OF THE INVENTIONThis invention relates in general to high velocity firearms and associated high velocity ammunition and deals more specifically with improvements in hand guns, particularly revolvers and high velocity ammunition for such firearms.
BACKGROUND OF THE INVENTIONBottleneck ammunition is well known in the firearm art and is usually used in rifles, particularly those of bolt-action type, and other long guns. A typical bottleneck ammunition cartridge includes an axially elongated cartridge case which has a cylindrical forward end portion within which a projectile or bullet is supported, a generally cylindrical rear end portion which has a base and a major diameter substantially greater than the diameter of the forward end portion, which carries the projectile. A neck-down portion disposed intermediate the front and rear portions of the cartridge case provide smooth transition there between. This bottleneck cartridge case configuration allows for the provision of a relatively large amount of a propellant charge to be contained within the rear portion of the case as is necessary for the attainment of a high muzzle velocity. The term “high velocity”, as hereinafter used, is intended to mean a muzzle velocity in excess of about 2,500 feet per second (ft./sec.).
Previous attempts to use bottleneck type cartridges with revolvers have proven generally unsuccessful. Such cartridges tend to expand when fired and drive the spent cartridge case in a rearward direction and toward the standing breech or bolster surface on the revolver frame at the immediate rear of the revolver cylinder. This condition may be attributed to some of the force generated by the gases of explosion in firing the cartridge being dissipated against the inner surfaces of the cylindrical and neck-down portions of the case, resulting in a net force vectoring the cartridge case in a rearward direction. Consequently, rotation of the revolver cylinder is likely to be inhibited if not precluded. It has also been found that if none of the cartridge cases are driven against the revolver frame with sufficient force to inhibit or preclude proper cylinder indexing rotation and or movement of the cylinder between open and closed positions relative to the revolver frame, extraction of the spent cases may be only marginally satisfactory if not totally unacceptable.
It is the general aim of the present invention to provide and improve ammunition system to allow for sufficient propellant charge or powder quantity to generate the energy necessary to achieve desired velocities while retaining the desired consistent functional characteristics of the firearm with which the ammunition is used.
It is a further aim of the present invention to provide improved handguns and particularly revolvers for effectively employing ammunition of the present invention while assuring consistent trouble free functionality of the action of the gun in which the cartridge is fired.
SUMMARY OF THE INVENTIONIn accordance with the present invention, a firearm for use with a round of high velocity ammunition also embodying the invention and having a projectile matching the caliber of the firearm bore and for engaging rifling in the bore. The projectile is carried by a sabot mounted within a diametrically enlarged cartridge case containing a propellant charge capable of propelling the projectile from the firearm at a high muzzle velocity. Further, and in accordance with the invention, the firearm has a chamber configured and dimensioned to cooperate with the cartridge case and the projectile to confine the nonmetallic sabot so that it will be compressed to a point of fragmentation and fragmetized by the dynamic forces generated by expansion of the gases of explosion when a high velocity propellant charge contained within the diametrically enlarged cartridge case. When the firearm is discharged, dynamic forces generated by the substantially instantaneous expansion of the gases of explosion compress and fragmentize the sabot. The sabot fragments, entrained in the escaping gases of explosion, travel through the firearm bore and escape from the firearm at its muzzle end.
BRIEF DESCRIPTION OF THE DRAWINGS
Turning now to the drawings, a high velocity firearm or revolver embodying the present invention and particularly adapted to fire high velocity ammunition embodying the invention is shown in
Referring now particularly to
The revolver 10 has an extractor of conventional type for removing spent cartridge cases from the charge holes or chambers 20,20 of the revolver cylinder 18 as shown in
A more complete disclosure of a presently preferred extractor mechanism for use in practicing the present invention is found in my earlier U.S. Pat. No. 5,218,148, which is hereby adopted by reference as part of this disclosure.
The illustrated revolver, which embodies the present invention, also includes a conventional cylinder indexing mechanism shown somewhat schematically in
It is anticipated that the ammunition system of the present invention will prove suitable for use with a wide variety of types of firearms. A revolver having operational characteristics which particularly suitable for use with ammunition in accordance with the present invention having been hereinbefore described ammunition embodying the present invention will now be considered and with particular reference to the inventive concepts of the firearm chamber within which it is received.
Referring now particularly to
The invention is preferably practiced with metal, rimed cartridges of centerfire type the case being preferably fabricated from brass. The case may be characterized as an axially elongated generally cylindrical thin walled shell which includes a radially disposed base 60 at its rear end percussion cap or primer is mounted centrally within a rearwardly open recess in the base wall and communicates with the interior of the case through a central bore opening 62. The major diameter of the case ranges from about 0.4 in. to about 0.5 in.
The invention maybe practiced with projectiles of various kinds. The presently preferred projectile 54 has an ogival head portion indicated at 64 which forms a transition with a generally cylindrical trailing portion 66 having an axial length approximately equal to the length of the end portion 64. In accordance with the invention, the projectile 54 is matched to the caliber of the firearm with which it is to be used and it is intended that the projectile engage the bore rifling in a conventional manner. Preferably, the present projectile has a major diameter ranging from about 0.264 in. to about 0.308 in.
A sabot is conventionally used as a carrier for a sub-caliber projectile engages the bore or rifling of a firearm from which the projectile is fixed. However, in accordance with the present invention, the only function of the sabot 56 is to position and support the relatively small diameter projectile in coaxial alignment with the substantially larger diameter case 52. The present sabot, is preferably molded otherwise formed from a somewhat resilient lightweight non metalic plastic material. It has an axially elongated generally cylindrical body with a coaxial stepped bore 68. The bore 68 has a generally cylindrical front-end portion 70 a rear-end portion 72 of somewhat smaller diameter and a radially disposed annular shoulder 74 which forms a transitional surface between the front portion and the dramatically reduced rear portions of the sabot bore 68. Generally radially disposed annular surfaces 76 and 78 coaxially surround the front and rear bore portions 70 and 72, substantially as shown. The axial length of the front portion 70 is substantially equal to the axial length of the projectile trailing portion 66 which is received in press fit within the front portion 70 of the sabot bore whereby the projectile 54 is located relative to sabot 56. The sabot 56 is, in turn and with the rear surface of the projectile in engagement with the shoulder 74 of the sabot received within the case 52 through the mouth thereof and is disposed in press fit engagement with the case. The forward end portion of the case which defines the mouth thereof is crimped into engagement with the sabot proximate the frontal bearing surface 76 of the sabot. Thus, the latter radially disposed frontal surface is exposed at the mouth of the cartridge for complementary abutting engagement with the transitional abutment surface of the chamber 20.
Referring now to
When the cartridge 50 is loaded in an associated cylinder chamber 20 the radial bearing surface at the forward-end of the sabot, is disposed in abutting engagement with the rearwardly facing annular abutment surface of the chamber.
When the round 50 is fired the substantially instantaneous increase in pressure generates dynamic forces acting upon the exposed rear surfaces of the projectile 54 and the sabot 56 sufficient to impart to the projectile the desired velocity while simultaneously compressing the sabot to a point of fracture at which point it acquires brittle characteristics so that the dynamic forces acting upon it cause it to fracture, and fragment. The resulting sabot fragments become entrained in the gases of explosion leaving the barrel through the muzzle of the firearm. Experimental firing has indicated that all of the relatively light sabot material leaves the barrel through the muzzle. However, should any sabot material remaining in the spent cartridge it will be removed from the chamber with the extracted spent cartridges. Initial indications are that sabot residue will not be a problem.
Referring now to
Yet another cartridge or round of ammunition embodying the present ammunition system is shown in
Claims
1. The combination comprising; a firearm, and a cartridge disposed in firing position within said firearm, said firearm having a generally cylindrical axially extending bore including a breech end and a forward or muzzle end, and a cylindrically stepped cartridge chamber in coaxial communication with said breech end, said chamber including a front portion having a diameter substantially equal to the diameter of said bore, a rear portion having a diameter substantially larger than the diameter of said front portion and a generally rearwardly facing annular abutment surface forming a transition between said front and rear portions for complimentary abutting engagement with a bearing surface on an associated cartridge received in a firing position within said chamber, said cartridge having a cylindrical case slideably received within said rear portion and including a mouth opening at its forward end and a base forming a closure for its rear end, a sabot received within said mouth and supported within said case, said sabot having a forwardly open projectile receiving bore an annular forwardly facing surface coaxially surrounding said projectile receiving bore and comprising said bearing surface, a projectile received and supported within said projectile receiving bore and extending for some distance into said forward portion, and a quantity of explosive propellant contained within said case rearward of said sabot for propelling said projectile out of said chamber and into and through said bore and for fracturing and fragmenting said sabot within said chamber and propelling the fragments of said sabot from said chamber into and through said bore and discharging said fragments at said muzzle end when said cartridge is fired.
2. The combination set forth in claim 1 wherein said abutment surface and said bearing surface comprise opposing radially disposed surfaces.
3. The combination set forth in claim 1 wherein said abutment surface comprises a generally conical rearwardly diverging surface centered on the axis of said chamber.
4. The combination set forth in claim 3 wherein said at least one bearing surface is defined by a conical surface of revolution centered on the axis of said cartridge.
5. The combination as set forth in claim 1 wherein said sabot is partially defined by a plurality of circumaxially spaced apart and axially forwardly projecting petals.
6. The combination set forth in claim 1 wherein said sabot has a plurality of distinct barring surfaces thereon.
7. The combination as set forth in claim 6 wherein said sabot is partially defined by a plurality of distinct axially forwardly extending petals and each of said petals defines in associated one of said distinct bearing surfaces.
8. The combination set forth in claim 1 wherein said projectile has a generally cylindrical rear portion received in press fit within said projectile receiving bore.
9. The combination set forth in claim 8 wherein said sabot is received and retained in press fit within said case.
10. The combination as set forth in claim 9 wherein said case is crimped radially inwardly at said mouth opening to further retain said sabot in said case.
11. The combination set forth in claim 1 wherein said projectile has an ogival forward portion forming a transition with a generally cylindrical trailing portion.
12. The combination set forth in claim 1 wherein said projectile receiving bore is a stepped bore including a rear portion, a front portion having a diameter larger than the diameter of said rear portion and a radially disposed and forwardly facing shoulder forming a transition between said front and rear portions.
13. The combination as set forth in claim 12 wherein said stepped bore comprises a blind bore and said sabot has a generally rearwardly facing end wall forming a closure for the rear end of said projectile receiving bore.
14. The combination as set forth in claim 13 wherein said rear wall has a generally radially disposed rear surface.
Type: Application
Filed: May 25, 2005
Publication Date: Jan 19, 2006
Applicant: Smith & Wesson Corp. (Springfield, MA)
Inventor: Richard Mochak (Russell, MA)
Application Number: 11/137,840
International Classification: F42B 14/06 (20060101);