Cartridged ammunition 1 for a grenade pistol includes a casing 10 made, for example, of plastic, the casing having an opening. A projectile 11 is disposed in the casing opening and includes a tracer charge and/or delayed-action charge 11b. A primer 13 and a propelling charge 14 are disposed in a cup 12 at the base of casing 10. The cup 12 is composed of two mutually concentric sleeves 12a and 12b, with the inner sleeve 12b being mounted so as to be slidable in the outer sleeve 12a and extendable in the manner of a telescope. The outer sleeve 12a has a free end section which is provided with an external thread 100 followed by an annular, predetermined, circumferential break location 12d. The base of projectile 11 includes a sleeve 17 provided with an internal thread which can be screwed onto the outer sleeve 12a of cup 12. A firing channel 12c is provided in the bottom or endwall 12e of the cup-shaped inner sleeve 12b, with such firing channel being oriented toward the tracer and/or delayed-action charge 11b. The result of this construction is that the ammunition can be assembled easily, and an almost constant initial velocity can be maintained despite fluctuating environmental conditions.

BACKGROUND OF THE INVENTION 
The invention relates to cartridged ammunition for a grenade pistol, the 
ammunition being of the type that includes a casing having an opening, a 
projectile which is disposed in the opening and which includes a payload 
and a transfer charge (such as a tracer charge and/or a delayed-action 
charge) for the payload, and primer and propelling charges disposed in a 
cup at the base of the casing. 
Cartridged ammunition for a grenade piston is disclosed in German 
Offenlegungs-Schrift (unexamined laid-open application) No. 3,149,430. The 
prior art ammunition includes a metal propelling charge container or 
casing (made, for example, of aluminum) with which the grenade body or the 
projectile is crimped together. Primer and propelling charges are disposed 
in a cup-shaped propelling charge cartridge which is screwed into the base 
of the casing. Radially extending discharge openings permit, after firing 
of the propelling charge, propagation of the propellant gases into the 
interior of the casing and charge the tail of the projectile with 
propellant gas pressure. 
To save costs, the casing of cartridged practice ammunition is preferably 
made of plastic and, since crimping is then not possible, the casing must 
be connected with the generally metal projectile body by glue. 
However, glue connections have the drawback that, in spite of careful 
matching and monitoring of all manufacturing parameters, even within one 
and the same lot, different degrees of extraction forces are observed. 
Additionally, the extraction force is a function of temperature and aging. 
Since, moreover, a considerably smaller propelling charge is employed for 
practice ammunition compared to combat ammunition, a particularly 
disadvantageous temperature dependency of the propellant gas pressure 
results when the propellant gases exit from the propelling charge 
cartridge or the propelling charge cup into the large-volume interior of 
the propelling charge casing. Both effects have the drawback of producing 
greatly deviating values for the initial velocity (V.sub.0) of the 
projectile, and reproducible firing results are almost impossible to 
attain. In connection with prior art projectiles it was additionally noted 
that, due to the escape of propellant gases into the interior of the 
casing, the tracer or delayed-action charge disposed in the tail section 
of the projectile is not fired with sufficient reliability. 
SUMMARY OF THE INVENTION 
It is an object of the invention to improve cartridged ammunition for a 
grenade pistol to the extent that the above-described drawbacks are 
avoided and, primarily because of a constant, almost temperature 
independent initial velocity, firing results are realized which are 
reproducible over a broad temperature range as well as reliable ignition 
of the tracer and/or delayed-action charge. 
Based on cartridged ammunition of the above defined type, this is 
accomplished by providing the cup which accommodates the priming and 
propelling charges in the form of two mutually concentric sleeves, with 
the inner sleeve being mounted in the outer sleeve so as to be slidable 
and extendable in the manner of a telescope. The inner sleeve is 
cup-shaped and is provided, in its bottom, with a firing channel oriented 
toward the tracer charge and the delayed-action charge. The outer sleeve 
has a free end section which is provided with an external thread followed 
by an annular, circumferential predetermined break location. The base of 
the projectile includes a sleeve having an internal thread which is 
screwed onto the outer sleeve of the cup.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
FIG. 1 is a longitudinal sectional view of a cartridged ammunition for a 
grenade pistol, for example having a caliber of 40 mm. Ammunition 1 
includes a casing 10 made, for example, of plastic, with a projectile 11 
being disposed in its opening. The projectile is equipped, for example, 
with a smoke charge 11a and a tracer charge and/or delayed-action charge 
11b disposed in the tail section of projectile 11. A primer 13 and a 
propelling charge 14 are accomodated in a cup 12 disposed at the base of 
casing 10. Cup 12 is composed of two mutually concentrically arranged 
sleeves 12a and 12b. Inner sleeve 12b is cup-shaped and is mounted so as 
to slide in outer sleeve 12a and to be extended in a telescoping manner. 
The inner sleeve 12b is provided in its bottom or end wall 12e with a 
firing channel 12c oriented toward the tracer and/or delayed-action charge 
11b in the tail section of projectile 11. 
The free end section of outer sleeve 12a extends into the interior of 10a 
of casing 10 and is provided with an external thread 100 followed by an 
annular, circumferential predetermied break location 12d. The base of 
projectile 11 is provided with a sleeve 17 provided with an internal 
thread so that it can be screwed onto outer sleeve 12a of cup 12. 
Due to the above-described structure, the ammunition can be assembled in a 
particularly easy and economical manner. After inserting cup 12 containing 
primer 13 and propelling charge 14 into the base of casing 10, an O-ring 
15 is initially placed into the annular, circumferential, predetermined 
break location 12d in the outer jacket of outer sleeve 12a of cup 12. 
Then, projectile 11 is screwded by means of sleeve 17 onto external thread 
100 of cup 12 until casing 10 and projectile 11 are seated flush on top of 
one another. Thus there is no gluing of the plastic casing 10 to 
projectile 11, so that all the above-described drawbacks connected with 
glue connections are avoided. If a metal casing is employed, crimping is 
no longer necessary. The O-ring 15 placed into predetermined break 
location 12d reliably seals the screw connection against any moisture that 
might still reach the interior 10a of casing 10, so that the cartridged 
ammunition remains reliably operational even after very long periods of 
storage. 
The functioning of the ammunition will be described with reference to FIGS. 
2 and 3. After the firing of propelling charge 14 by way of primer 13, a 
gas pressure develops in the propelling charge chamber in cup 12, which 
causes the annular predetermined, break location 12d thus stressed with 
tension to yield only after a predetermined and easily reproduced pressure 
level is reached. 
After predetermined break location 12d has been torn apart, the propelling 
charge pressure causes projectile 11 to be accelerated and begins to push 
it out of propelling charge casing 10. However, the volume available for 
the propellant gases is enlarged only comparatively slightly since the 
cup-shaped inner sleeve 12b (which, as previously noted is slidably 
mounted so as to be extended in a telescope-like manner in outer sleeve 
12a of cup 12) is pressed out of outer sleeve 12a in a telescope-like 
manner when it participates in the movement of the projectile. This limits 
the volume of the propellant gas and prevents escape of propellant gases 
into the interior 10a of casing 10. Only after projectile 11 leaves the 
cartridge base--as shown in FIG. 3--and enters the rifling of the gun 
barrel (not shown), practically at its final velocity, will inner sleeve 
12b, which is now completely separated from outer sleeve 12a, open a path 
for the propellant gases to enter into the interior 10a of casing 10. Due 
to the very tightly limited small volume in which the propellant gases are 
initially able to propagate, there results, in an advantageous manner, a 
greatly reduced temperature dependence of the propellant gas pressure 
which again, in spite of greatly differing ambient temperatures, leads to 
a constant initial velocity for projectile 11 and thus to reproducible 
firing results. 
Limiting the propellant gas volume to a volume that is small initially is 
known per se from German Auslegeschrift (examined laid-open application) 
No. 2,262,981. However, in that publication, a ductile cup is provided in 
a disadvantageous manner to delimit the propelling charge chamber which, 
under the influence of the propellant gases, must be bulged out by 
deformation forces. 
The firing channel 12c in the end wall 12e of cup-shaped inner sleeve 12b 
oriented toward the tracer and/or delayed-action charge 11b disposed in 
the tail section of projectile 11. Immediately after firing of propelling 
charge 14, hot propellant gases are thus able to pass through this firing 
channel 12c. This permits--in contrast to conventional ammunition--a 
completely reliable firing of the tracer and/or delayed-action charge 11b. 
Tracer and/or delayed-action charge 11b simultaneously serves to provide 
for firing, possibly with a time delay, of a payload transported in 
projectile 11, here, for example, a smoke charge 11a. For this purpose, 
casing 110 which accommodates the tracer and/or delayed-action charge 11b 
is pyrotechnically coupled with the smoke charge 11a in such a manner that 
toward the end of the burning period of tracer and/or delayed-action 
charge 11b, smoke charge 11a is also fired. Thus pressure builds up in 
projectile 11 which, after causing an O-ring 16 to be blown off, permits 
clouds of smoke 19 to escape, as shown in FIG. 3, preferably through bores 
18 uniformly distributed in an annular pattern. In this way, an effective 
smoke effect is produced even while the projectile 11 is in its last phase 
of flight, before it hits the ground. Instead of the smoke charge 11a, 
another payload, such as, for example, a flash, muzzle report, dye and/or 
fogging charge, may of course also be disposed in projectile 11. 
Advantageous modifications of the invention will be described with 
reference to FIGS. 4 to 7. FIG. 4 is a longitudinal sectional view of a 
practice cartridge, FIG. 5 is a side view of the cup 12' which is shown to 
a larger scale; FIG. 6 is a sectional view--again enlarged--through the 
wall of cup 12' in the region of recesses 50; and FIG. 7 is a side view of 
a cup 12' in another embodiment. 
The advantageous modifications of the ammunition 1' differ from the 
embodiment according to FIGS. 1 to 3 primarily in that recesses 50 are 
provided in the wall of cup 12' so as to connect the chamber of propelling 
charge 14 with the interior 10a of casing 10. Each recess 50 may have a 
diameter between 0.5 mm and 2.5 mm, and preferably about 2 mm. These 
recesses 50 are preferably uniformly distributed in an annular pattern, in 
the embodiment according to FIG. 5 to 6, below predetermined break 
location 12d. 
In one embodiment of the invention, four recesses 50 are provided at a 
mutual spacing of 90.degree.. Due to the provision of recesses 50, after 
propelling charge 14 is fired the interior 10a of casing 10 is also 
charged with a gas pressure right from the beginning, albeit a lower gas 
pressure. In view of the large difference in volume between the propelling 
charge chamber within cup 12' and the interior 10a of casing 10, the 
pressure value encountered in interior 10a is lower, for example only 1/10 
of the pressure in the interior of cup 12'. Since, however, projectile 11 
delimits interior 10a of casing 10 with a relatively large surface area, a 
great force is exerted on projectile 11 in spite of the relatively low gas 
pressure in interior 10a, which force contributes to the separation 
between projectile 11 and casing 10. 
In this modification of the invention, the predetermined break location 12d 
has such dimensions that it could not be destroyed merely on the basis of 
the propelling charge pressure developed in the interior of cup 12'. For 
example, predetermined break location 12d could be designed so that it 
would be destroyed only under a load of 750 kp. However, an internal 
pressure of about 400 bar in the interior of cup 12a and a surface area of 
about 1.25 cm.sup.2 would develop only a force of about 500 kg. Only a 
combination of the forces acting on the projectile, due to the pressure in 
the interior of cup 12a and in the interior 10a of casing 10, makes it 
possible to destroy predetermined break location 12d and accelerate 
projectile 11. The contributing pressure in interior 10a of casing 10 is 
here about 50 bar, which exerts an additional force of 500 kp on the base 
surface of the projectile of about 10 cm.sup.2. Thus, only the sum of the 
above mentioned force components exceeds the break resistance of 
predetermined break location 12d. 
Due to the face that interior 10a is already preheated by the penetrated 
propellant gases and is charged with a certain pressure level, a 
significantly greater precision with respect to reproducibility of the 
initial velocity and range of projectile 11 can be realized. 
In one embodiment of the invention, the outer diameter of casing 10 was 
about 38 mm, the inner diameter of cup 12' about 12 to 13 mm. Four 
recesses 50, each having a maximum diameter of about 2 mm, were disposed 
in cup 12' at mutual spacings of 90.degree.. The weight of the projectile 
was about 180 g. With propellant charge 14 having a weight of about 0.35 
g, a pressure of about 500 bar developed in the interior of cup 12', while 
about 1/10 of this pressure value, i.e. 50 bar, was noted in interior 10a 
of casing 10. After numerous test firings, a very uniform initial velocity 
was noted for projectile 11 and the range remained constant with a very 
low standard deviation, so that all requirements of the customer could be 
met. The spread in range was always below about 25 cm per 100 m, compared 
to about 45 cm per 100 m for conventional ammunition. The standard 
deviation of the initial velocity V.sub.o was always less than 1 m 
sec.sup.-1. Thus the values required by the customer could be maintained 
without difficulty. 
To improve the storage life of the cartridged ammunition and to make it 
less susceptible to moisture, it is advisable to cover recesses 50 with a 
membrane 50a--as shown in FIG. 6--which is not pressure resistant but is 
destroyed immediately after firing of propelling charge 14. This membrane 
50a may be produced, for example, of a thin plastic or metal foil. 
In a further embodiment of the invention, recesses 50 in cup 12' are 
advisably disposed so as to lie within annular, predetermined break 
location 12d (FIG. 7). This embodiment has the advantage that no separate 
cover is required for recesses 50, for example as shown in FIG. 6. 
Reliable sealing of recesses 50 is simultaneously effected by O-ring 15, 
which is inserted into the predetermined break location 12d so as to seal 
the screw connection between sleeve 17 and cup 12'.