[0001] The present invention pertains to small-shot cartridges for smooth-bore shotguns
or shooting rifles, and pertains in particular to a wad for steel small shot.
[0002] As is known, such cartridges comprise a case having an end percussion cap and containing
a firing charge and bullets consisting of a plurality of lead or steel small shot.
In some cartridges, the charge and the small shot may be separated by a wad, which
can be shaped like a cup for containing the small shot proper and for functioning
as a concentrator of the small-shot cluster.
[0003] The use of steel small shot is, on the one hand, preferred compared to the use of
lead small shot because of the known toxic action of the latter, and on the other
hand, it is limited only to those rifles, whose barrel has a very smooth choke, called
in slang "slippery union." In fact, steel small shot, unlike the lead small shot,
is neither compressed nor crushed, passing through the choke of the mouth of the barrel
and, if a common choke with a truncated cone or straight union is used, it runs the
risk of making the barrel explode.
[0004] The object of the present invention is to propose a cartridge wad for smooth-bore
shotguns or shooting rifles, which makes it possible to use steel small shot with
any type of barrel and related choke.
[0005] The object is accomplished with a wad for cartridges of smooth-bore shotguns or shooting
rifles, having a base turned towards the firing charge contained in the case, and
a cylindrical lateral wall that extends from said base towards the firing direction,
in which said cylindrical lateral wall of the wad and the case define between them
an annular space intended to prevent the expansion of the small shot over the entire
cross section of the barrel. In practice, the diameter of the cylindrical lateral
wall of the wad is less than that of its base, said lateral wall preventing the cluster
of small shot produced by the explosion from striking against the bore of the barrel.
[0006] In any case, greater details of the present invention and its embodiment variants
will become more evident from the description below with reference to the attached,
indicative and nonlimiting, drawings. The various features of novelty which characterize
the invention are pointed out with particularity in the claims annexed to and forming
a part of this disclosure. For a better understanding of the invention, and its operating
advantages and specific objects attained by its uses, reference is made to the accompanying
drawings and descriptive matter in which preferred embodiments of the invention are
illustrated.
[0007] Figure 1 is an axial section of a cartridge, in which is inserted a wad for steel
small shot according to a first embodiment.
[0008] Figure 2 is an axial section of a wad in a second embodiment.
[0009] Figures 3, 4 and 5 are perspective views of a wad for steel small shot according
to other embodiments.
[0010] Referring to the drawings in particular, Figure 1 shows a cartridge for smooth-bore
shotguns for steel small shot, comprising a case 11 having an end percussion cap 12
and containing, in order from the end, a firing charge 13 and a charge of steel small
shot 14. The small shot is arranged in a wad 15 in the form of a cup, or made up of
a base 16 turned towards the firing charge 13 and of a cylindrical lateral wall 17
that extends from this base 16 and that is open forwards in the firing direction.
The case 11 is closed at the top by a disk 18.
[0011] According to the present invention, the diameter of the cylindrical lateral wall
17 of the wad is less than that of its base 16, so that the case 11 and said cylindrical
lateral wall 17 define a space 19 between them. For example, the diameter of the cylindrical
lateral wall 17 may be one or two gauges less than that of its base 16, i.e., of the
cartridge. The cylindrical lateral wall 17 thus limits the expansion of the cluster
of steel small shot over a section suitable for passage through the choke of the barrel
of the gun, preventing the shot from striking against the bore of the barrel.
[0012] In addition, the wad 15 may be provided, preferably close to its opening, with a
whole or segmented, annular element 20, with a centering and guide function for the
wad during its sliding in the barrel of the rifle.
[0013] Moreover, the annular portion 16' of the base 16 of the wad, which protrudes in relation
to the cylindrical lateral wall 17, may have a conical course, converging downwards
to function as an air intake and to contribute to the slowing down of the wad in relation
to the small shot following the front impact with the air.
[0014] In a second embodiment illustrated in Figure 2, the air intake for the wad 21 is
embodied by making a series of longitudinal cuts 22 along an end annular portion of
the lateral wall of the wad. Following the impact with the air, this end portion of
the wad 21 opens thanks to the presence of the longitudinal cuts 22. In this case,
the annular guide element 20 is provided just below the end annular portion.
[0015] Figure 3 shows a wad 23 similar to that described in Figure 1, but in which, for
its guiding in the barrel of the rifle, a plurality of longitudinal ribs 24 are provided
along the lateral wall 17.
[0016] In a fourth embodiment shown in Figure 4, the wad 25 has two concentric cylindrical
walls 26, 27, the more external one 26 having a diameter equal to the gauge of the
cartridge and the more internal one 27 being one or two gauges less for containing
the small shot. Longitudinal cuts 28 can be provided on the external wall 26 to make
possible the opening of the wall proper after the impact with the air.
[0017] Figure 5 shows another wad 29 similar to the one in the previous Figure (4), but
in which the external wall 30, having longitudinal cuts 31, only partially surrounds
the internal wall 32 from the base 33 of the wad. For example, good ballistic results
were obtained with an external wall 30 with a height equal to about one third of the
internal one 32.
[0018] While specific embodiments of the invention have been shown and described in detail
to illustrate the application of the principles of the invention, it will be understood
that the invention may be embodied otherwise without departing from such principles.
1. A smooth-bore shotgun or shooting rifle cartridge and wad comprising: a case (11)
having an end percussion cap (12) and containing a firing charge (13) in said case
and a wad (15) for accommodating small shot, said wad (15, 21, 23) having a base (16)
turned towards the firing charge (13) and a cylindrical lateral wall (17) extending
from a base towards a direction of firing, characterized in that said cylindrical lateral wall (17) and the case (11) defining an annular space (19)
between them for substantially preventing an expansion of the small shot over a cross
section of the barrel.
2. A cartridge and wad in accordance with claim 1, wherein the base (16) has a diameter
equal to a gauge of the cartridge and a diameter of the cylindrical lateral wall (17)
is less than the diameter of said base.
3. A cartridge and wad in accordance with claim 2, in which the diameter of the cylindrical
lateral wall (17) is at least one gauge less than the gauge of the base (16).
4. A cartridge and wad in accordance with any one of the preceding claims, wherein the
wad includes a whole or segmented annular element (20) close to an opening of the
case for centering and guiding the wad during its sliding in the barrel of the rifle.
5. A cartridge and wad in accordance with claim 4, wherein the wad has a plurality of
longitudinal cuts (22) along an end annular portion of the lateral wall of the wad,
the annular element (20) being provided below said end annular portion.
6. A cartridge and wad in accordance with any one of claims 1 to 3, wherein said lateral
wall has a plurality of longitudinal ribs (24) for centering and guiding the wad during
its sliding in the barrel of the rifle.
7. A cartridge and wad in accordance with any one of claims 2 to 6, wherein said base
(18) has an annular upper surface (16) protruding externally from the cylindrical
lateral wall (17) and the annular surface (16) has a conical course converging downwards.
8. A cartridge and wad for steel small shot for cartridges of smooth-bore shotguns or
shooting rifles, comprising: a case having an end percussion cap (12) and containing
a firing charge (13) and a wad (25, 29) above the firing charge for accommodating
steel small shot, said wad having a base (33) turned towards said firing charge (13)
and two concentric cylindrical walls (26, 27, 30, 32) extending from said base towards
the direction of firing, said walls including an external wall (26, 30) having a diameter
equal to the gauge of the cartridge and an internal wall (27, 32) intended for accommodating
the steel small shot, said internal wall having a diameter less than the gauge of
the cartridge by one gauge.
9. A cartridge and wad in accordance with claim 8, wherein said external wall (26, 30)
has a plurality of longitudinal cuts (28, 31).
10. A cartridge and wad in accordance with claim 8 or 9, wherein said external wall (26,
30) has a height equal to about one third of said internal wall (32).