US3063376A - Slug for shotgun - Google Patents

Description

Nov. 13, 1962 E. B. POWELL sum FOR SHOTGUN Filed NOV. 12, 1959 IIIIIAYIIIIIII'III IN VEN TOR. 5 51005 POWELL BY w -w 3,063,376 SLUG FOR SHOTGUN Edward Baden Powell, 250 N. Orange Grove Ave, Pasadena, Calif. Filed Nov. 12, 1959, Ser. No. 852,269 1 Claim. ((11. 102-51) This invention relates to projectiles and has been primarily designed as a shotgun slug.

In the case of rifles, the spiral grooves called rifling on the interior of the gun barrel impart a rotational motion or spinning to the rifle bullet that is conducive to its retaining a true course. In the case of smooth bore guns such as shotguns, no riding is present to impart to a projectile a rotary or spinning motion that will tend to cause it to retain its true course without wobbling or without having a tendency to turn end-over-end.

A primary object of the present invention is to provide a projectile for guns having smooth bores consisting of a projectile head having associated therewith a rearwardly extending rearwardly open skirt. Openings are formed in the Walls of the skirt and adjacent these openings there are configurations on the skirt so designed or so shaped that gases, generated by the propellant of the projectile, on passing through the openings will impart a rotary or spinning motion to the projectile. In the preferred form of construction, the mass of the skirt is no greater than, and is usually less than, the mass of the projectile head so that the center of gravity of the entire projectile is either at, or forwardly of, the geometric center of the projectile. Also, in the preferred form of construction, the maximum external diameter of the skirt, which is relatively thin walled, is slightly larger than the maximum external diameter of the projectile head, which is either solid or thick walled, so that the skirt may have an opportunity to contract as occasion requires in passing through gun barrels having choke bores.

Another object of the invention is to provide an improved shotgun shell designed to fire a shotgun slug and impart to the slug a rotary or spinning motion.

Another object of the invention is to provide a shotgun shell that does not require the conventional wads which are used to seal against the walls of the barrel and thus confine gases generated by the propellant. These wads are also used to exert and maintain pressure on the propellant when loading in order to inusre uniform combustion and velocity of the projectile from one shell to another. These wads are resilient and are not always reliable in producing the desired uniformity of compression. By mean of the improved shotgun shell the use of wads can be eliminated. The desired seal against the walls of the barrel can nevertheless be retained and uniform compression of the propellant is possible.

With the foregoing and other objects in view, which will be made manifest in the following detailed description and specifically pointed out in the appended claim, referenece is had to the accompanying drawing for an illustrative embodiment of the invention, wherein:

FIGURE 1 is a longitudinal vertical section through a shotgun shell embodying the present invention, the explosive or propellant being shown removed from the shell for the purpose of illustrating details of construction;

PIG. 2'is a sectional view taken substantially upon the line 2'"2 of FIG. 1 in the direction indicated;

FIG. 3 is a view illustrating the projectile as having just issued from the end of a smooth bore gun barrel; and

FIG. 4 is a perspective view, parts being broken away and shown in section, of the projectile.

3,063,376 Patented Nov. 13, 1962 Referring to the accompanying drawing wherein similar reference characters designate similar parts throughout, the improved shotgun shell consists of shell case 10 of conventional construction having the usual percussion cap 11 by which the gun powder or propellant for the projectile can be ignited on firing in the conventional manner. The projectile embodying the present invention comprises a projectile head 12 usually formed of lead or heavy metal. A hollow rearwardly open skirt 13 is associated with the head, which skirt may be formed integrally with the head or may be in the form of a section of copper or aluminum tubing, the forward edge of which is crimped against the sides of the head 12, as indicated at 14. The skirt telescopically fits inside of the shell case 10 and has openings 15 formed in the walls thereof. These openings may be formed by striking inwardly, portions of the skirt indicated at 16, to form inwardly extending spiral or helical configurations adjacent the opening, which are designed to impart rotary motion to the projectile when gases generated by the gun powder or propellant are allowed to pass through the openings 15 at high velocity. The portions 16 are triangular in form and along one longitudinally extending edge they are integral with and attached to the skirt. Along another longitudinally extending edge and along a transversely extending edge the triangular portions are detached and curve inwardly from the cylindrical skirt. In the preferred form of construction, the maximum diameter of the skirt 13 is located rearwardly of the head 12 and is greaer than the maximum diameter of the head "12. As the skirt 1B is of relatively thin wall construction, this skirt may contract slightly as occasion may require, when the projectile is discharged through a choke bore gun barrel, indicated at 17.

If the shell case .10 is formed of metal, the walls of the shell case may be crimped past reduced head diameter at r18. On the other hand, if the shell case has its walls formed of paper, the crimp at the outer end of the walls may extend partially over the head past 14 to retain the projectile and shell case in assembled relationship. The entire interior of the projectile is usually filled with the propellant, not shown, such as gun powder. When the shotgun shell embodying the present invention is placed in the chamber of a shotgun and is discharged, the projectile is forced out of the gun barrel by the gases generated by the burning gun powder. These gases are confined between the front of the base of the shell case and the rear of the projectile head. During the movement of the projectile through the smooth bore gun barrel, due to the fact that the gases are confined and cannot exist through the openings 15, no rotary motion is imparted to the projectile. However, as soon as the projectile leaves the end of the gun barrel 17, gases under high velocity and under considerable pressure also issue from the gun barrel and continue to be effective on the rear of the projectile. Some of these gases expand laterally but a substantial portion of them follow the projectile, and due to their pressure, flow laterally out through the then exposed openings 15. These gases on flowing past the vanes or spiral configurations 16, cause a rotary or spinning motion to be imparted to the projectile, which is desired to cause the slug to remain on its intended course. As the mass of the skirt 13 is preferably never greater than the mass of the head 12, it will be appreciated that the center of gravity of the projectile is either at or forwardly of the geometrical center of the projectile. Usual ly, it is desired to have the center of gravity decidedly forward of the geometric center. As with this arrangement, tendency of the projectile to wobble or to turn end-over-end in flight is eliminated.

It will be appreciated by those skilled in the art that the improved projectile can be very easily and economically manufactured and will enable projectiles discharged from smooth bore guns to have the desired rotary or spinning motion imparted to them. The number of vanes or configurations 16, and the degree of their pitch will vary with the type of gun powder or propellant employed. It is desirable, however, to have the opening and configurations equally spaced circumferentially about the skirt.

In the improved shell the volume inside of the metal skirt can be regulated and maintained to accept and confine a precise quantity of propellant which, when the skirt is bottomed against the base of the shell, can always have and provide the same degree of compression of the propellant.

While the preferred form of construction embodying the present invention contemplates that the skirt 13 be equipped with the inwardly extending spiral or helical configurations to impart a rotary motion to the projectile during flight as above explained. The improved projectile possesses advantages even when these configurations are omitted and the skirt is left imperforate. Heretofore, in shotgun slugs where the projectile is formed of lead or the equivalent, or where a projectile has been equipped with a rearwardly extending skirt, the fit between the head of the projectile and the Walls of the gun barrel has been intentionally left somewhat loose to facilitate passage through the barrel particularly if it has a choke bore. Even where the head of the projectile has had an integral skirt the skirt has heretofore been of thick-walled design and the fit between the skirt and the walls of the gun barrel has been left loose. The looseness of the fit has been conducive to cause the projectile to wobble or turn in flight. In the improved construction the skirt is of relatively thin-walled design and if formed of copper or aluminum the skirt possesses some degree of flexibility and resiliency. Consequently, even if the spiral configurations are omitted the skirt can be expanded by the [3, pressure of the gases generated by the propellant to fit snugly against the Walls of the barrel and thus maintain sealing contact therewith and the skirt can also readily contract as required to pass through a barrel having a choke bore.

Various changes may be made in the details of construction without departing from the spirit and scope of the invention as defined by the appended claim.

I claim:

A projectile for a gun comprising a body having a rearwardly open cylindrical skirt in the walls of which there are openings, there being a triangular portion of the skirt adjacent each opening having one longitudinally extending edge attached to and integral with the skirt, another longitudinally extending edge detached from the skirt and curving inwardly therefrom and a third edge also detached from the skirt and curving inwardly therefrom and facing toward the rear of the projectile whereby in the course of firing the projectile from a gun barrel, when the openings are exposed, propellant gases passing through the openings will in so act upon surfaces of the triangular portions imparting an axial spin to the projectile.

References Cited in the file of this patent UNITED STATES PATENTS 37,940 Plant Mar. 17, 1863 517,560 Ashley Apr. 3, 1894 1,063,905 Beckmann June 13, 1913 1,376,316 Chilowsky Apr. 26, 1921 2,597,878 Banning May 16, 1950 2,559,955 Hartwell July 10, 1951 2,573,362 Rouse Oct. 30, 1951 2,926,612 Olin Mar. 1, 1960 FOREIGN PATENTS 14,000 Great Britain June 24, 1896

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