US 3120188 A
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Feb. 4, 1964 w, KREUZER 3,120,188
LEAD SHOTGUN PELLETS Filed Aug. 22, 1961 'SHOTGUN SHELL STEEL DRUM CONTAIN/N6 LEAD SHOTGUN PELLLTS, R07717ED AT 68 RPM 7'0 COAT PELLETS WITH LEAD OXIDE INVENTOR WALTER KREUZER.
BMQMQMUQQWSMM ATTO EYS United States Patent 3,129,188 LEAD SHUTGUN I'ELLETS Walter Krenzer, Troisdor dlberlar, Germany, assignor to Dynamit Nobel A.G., Troisdori, Bezirlr (Iologne, Germany, a German corporation Filed Aug. 22, 1961, Ser. No. 133,227 Claims priority, application Germany Aug. 24, 196i 4 marinas. (Cl. 1ti22.5)
This invention relates to improved lead shot pellets for shotgun shells.
The lead shot pellets conventionally used in shotgun shells have a tendency upon firing to flow together and thus agglomerate, forming larger particles. This detrimentally affects the shot pattern, may constitute a danger in that the agglomerated pellets may act as a larger ball increasing the range and danger zone over that which would normally be expected. The user may thus consider an object safely out of range but the agglomerated shot acting as a ball may reach this object. Furthermore, the conventional lead shot pellets have a tendency of fouling the shotgun barrel with lead which requires cleaning with wire coils or brushes.
One object of this invention is a lead shot for shotgun shells which avoids the above-mentioned disadvantages.
A further object of this invention is a shotgun shell containing this shot.
A still further object of this invention is a process for the production of such improved lead shot.
These and still further objects will become apparent from the following description read in conjunction with the drawings in which:
FIG. 1 is a perspective view of a conventional shotgun shell with a portion of the casing cut away to illustrate the shot,
FIG. 2 is a cross section of a shotgun pellet in accordance with the invention, and
FIG. 3 is a diagrammatic perspective view showing a steel drum in which the method in accordance with the invention is carried out.
In accordance with the invention it has been surprisingly found that the above-mentioned disadvantages can be avoided if the lead shot pellets are provided with a surface coating of a lead oxide and that conventional lead shotgun pellets may be provided with such a protective lead oxide coating in a very simple and economical manner.
The lead shot pellets in accordance with the invention comprise the well-known in conventional lead shot pellets for shotgun shells of the standard sizes and configurations but which are provided with a surface coating of lead oxide of a thickness of 5 to 40a.
The lead oxide may be any known or conventional lead oxide such as lead monoxide (litharge), lead dioxide or rninium, or mixtures of these oxides.
In accordance with the invention the protective coating of the lead oxide on the individual shot pellets may be very simply and economically formed by merely tumbling a conventional lead shot in a drum such as, for example, a hexagonal steel drum at a low rotary speed as, for example, 60 rpm. for a period of time sufficient to form the lead oxide coating between 5 and 40 1. thickness. Normally, a lead oxide coating of this thickness will build up after about four hours of tumbling.
FIG. 3 of the drawing diagrammatically illustrates the method in accordance with the invention by showing a steel drum in which the lead shotgun pellets are tumbled in order to produce the lead oxide coating.
In accordance with a further embodiment of the invention, it has been found that the formation of the lead oxide coating may be facilitated by adding small amounts 3,l2h,l88 ?atented Feb. 1964 of lead oxide as, for example, less than 0.1% by Weight to the shot prior or during the tumbling. With this addition the tumbling time can be substantially reduced.
FIG. 2 shows a cross section of a lead shotgun pellet having the lead oxide coating as produced in accordance with the invention.
FIG. 1 of the drawing shows a conventional shotgun shell containing the lead shot with the lead oxide surface coating in accordance with the invention. The shells produced with this coated shot eliminate the prior art problems so that upon firing the individual pellets will remain discrete and will not fuse together.
Furthermore, the lead fouling of the shotgun barrel is avoided and with the surface of the individual shot pellets insulated, the same are no longer attacked by the hot powder gases. The insulating layer prevents a deformation of the marginal pellets so that the same no longer become soft and are prevented from fusing together. In general, the coating acts as a protective coating on the individual pellets, enhancing their adaptability for their intended use.
The following examples are given by way of illustration and not limitation:
Example I 50 kilograms of standard lead shot 96.3% soft smelter lead, 3.5% antimony and 0.2% arsenic) are tumbled for four hours in a hexagonal steel drum at 68 revolutions per minute. The individual shot pellets then exhibit a surface coating 30w. thick, which is resistant to more than 820 C. and consists principally of lead oxide. The shot is loaded into a standard 12 gauge shotgun shell as is shown in the drawing and upon firing gives an excellent pattern, with the individual pellets remaining discrete, and does not cause a lead fouling of the barrel.
Example 2 Example 1 was repeated except that 20 grams of lead oxide was added to the drum prior to the tumbling. In this case the surface coating of 30; thickness was obtained after one hour of tumbling.
The invention has been described in detail with reference to certain specific embodiments. Various changes and modifications which fall within the spirit of the invention and scope of the appended claims become apparent to the skilled artisan. The invention is therefore only intended to be limited by the appended claims or their equivalents wherein I have endeavored to claim all inherent novelty.
1. Process for the formation of a protective coating on lead shot for shotgun shells which comprises tumbling the shot in the presence of oxygen for a period of time suflicient to produce a lead oxide coating from 5 to 40 thick on the individual shot particles.
2. Process according to claim 1 in which said tumbling is effected in the presence of a minor quantity of added lead oxide.
3. Process according to claim 1 in which said tumbling is elfected in a steel drum.
4. Lead shot pellets for shotgun shell having a protective surface coating of lead oxide about 5 to 40 thick, said protective surface coating being formed by the process of tumbling the shot in the presence of oxygen for a period of time suflicient to produce the lead oxide coating of from 5 to 40a thickness on the individual shot particles.
References Qited in the file of this patent UNITED STATES PATENTS 2,919,647 Dear et a1. Jan. 5, 1960