COSTRUZIONI MECCANICHE Soc. p. Azioni
ROMA
S. С. M. MOD. 64
STANDARD HAND AND RIFLE GRENADE
COSTRUZIONI MECCANICHE Soc. p. Azioni
ROMA
S. С. M. MOD. 64
STANDARD HAND AND RIFLE GRENADE
S. С. M. MOD. 64
Standard Hand And Rifle Grenade
DESIGN FEATURES
The « Multiple » is a combined grenade, incorporating an offensive hand
grenade with a defensive and a rifle grenade, designed for use on living targets
or against light armour.
Fig. i
The grenade consists essentially of
two independent deflagrating elements
(pratically two grenades linked toge-
ther) .
The distribution of the single weights,
all actively contributing to percussion,
and the kinematic configuration based on
swiveling hinges, eliminating sliding fric-
tion, provide the grenade with a high de-
gree of sensitivity at any angle of impact
(reliability of operation).
The safety device, which guarantee the
structural stability of the grenade at the
highest external stress levels, provide
also the maximum security against pre-
mature explosions, as the firing pins are
far removed from the detonators.
A longitudinal section of the grenade,
in the offensive configurations is shown
in fig. 1.
DETAILED DESCRIPTION
The grenade consists essentially of two identical main parts, each con-
taining a bursting charge of 770 grains (avoirdupois) of compressed TNT,
with a detonator-booster housing.
These two main parts are linked to a central body (percussion fuze
mechanism) housing the firing pins and the safety devices.
High-strength corrosion resistant steel bands — acting as launch and
handling safety devices — keep the two hinged elements of the grenade
separated. The steel bands clamp the main parts rigidly together, and also
block the firing pins in a position so far removed from the centerline of the
detonators, as to prevent, in any case, contact between the pins and the
detonators. The bands are secured on the grenade by means of a sliding
clamp which carries on one end a rubber cloth strap.
A thin metal strip, coiled under the external steel bands and having
a small pin attached to its innermost end, keeps the firing pins distant from
the detonators. The gradual uncoiling of this strip along the trajectory permits
the activation of the grenade only after it has travelled for a few yards from
the launching point.
Fig. 2
Offensive grenade
(scale 1:1)
Fig. 3
Defensive grenade
(Scale 1:1)
In this way, should the grenade strike against an obstacle near the laun-
cher, it will not explode, remaining definitely deactivated by its automatic
safety device.
All the main parts of the grenade are in aluminum and aluminum alloys,
and are designed to fracture in a great number of minute fragments with a
range limited (on purpose) to 20 yards approximately.
The simultaneous explosion of 1540 grains of TNT, compressed in two
separately primed forms, produces a
strong shock effect.
The grenade, as described, conforms
to requirements of the offensive hand
grenade (fig. 2). In this configuration
it is 3.54” long with an OD of 2.05”
and has a gross weight of 7.41 oz
(avoirdupois).
The defensive hand grenade (fig. 3)
configuration is obtained by fitting on
the two cylindrical parts of the offensive
grenade two steel coils of square section
and predetermined fragmentation. Gross
weight is 14.82 oz and the range over
55 yards.
The rifle grenade configuration (fig. 4)
is obtained by inserting one end of the
defensive grenade in a suitable finned tail
cone, and screwing on the opposite end
an ogive (containing 770 grains of com-
pressed TNT). The gross weight of the
rifle grenade configuration is 1 lb 71/г
oz and its total bursting charge amounts
to 5.29 oz of compressed TNT. This gre-
nade, can be launched with rifles fitted
with .866” launching tubes and regula-
tion launching ammunition (U.S.A. М3 -
Fig. 4
Rifle grenade (Scale 1:2)
F.N. gr 2, 3 NATO etc.) and can achieve a maximum range of 220 yards.
In order to avoid mistakes in the launch ammunition, every tail cone
carries the round which should be used in launching the grenade.
PACKING
The grenades are packed in wooden shipping boxes, each containing
two hermetically sealed metal boxes holding 40 offensive hand grenades
(without detonators-boosters) and 80 detonators-boosters respectively, arran-
ged in shock-proof panels (fig. 5).
Between the two metal boxes, arranged in separate compartments, there
are 10 ogives/tail-cones and 80 fragmentation coils. Each tail-cone houses
one launching round.
The offensive grenades, the ogives/tail-cones and the fragmentation
coils, are kept apart by wood and cardboard separation panels.
The shipping boxes are equipped wth two handles for transportation and
are reinforced with suitable steel bars. The box covers are hinged and held in
place by two swivel clamps. The swivel clamps may be replaced by two metal
strips holding down the covers.
Overall dimensions
30.4” x 11.1” x 11.6”
Gross weight
72 lbs 6 oz approx.
Provision has been made for an alternate shipping box (fig. 6), contain-
ing — in a similar arrangement — 40 defensive grenades, 80 detonators-bo-
osters and 8 ogives/tail-cones. The gross weight of the alternate shipping
box is 64 lbs.
Fig. 5
Fig. 6
USE OF THE GRENADE
The grenades are furnished with the detonators-booster dismounted, and
must be activated before use. This is accomplished by inserting two detona-
tors-boosters, one at each end of the grenade, leaving all the safety devices on
and intact. Each detonator-booster should be pushed in the housing until it is
securely attached to it. This is evidenced by a slight rotation of the detonator-
booster (fig. 7).
The application on each of the two main parts of the grenade, of a fragmen-
tation coil, suffices to transform the offensive grenade into a defensive one
The application is facilitated by a slight clock-wise rotation of the coils, which
should be continued until the coils are completely inserted on the grenade
Fig. 8
The disassembly of the fragmentation coils, whenever desired, is ac-
complished by a slight clock-wise rotation of each coil (fig. 9), after having
grasped it at its upper end.
Fig. 9
The assembly of the rifle grenade is obtained by screwing tightly on the
fragmentation coil (rubber strap side) the finned tail cone, and the ogive on
the other end of the grenade.
1) LAUNCHING OF HAND GRENADE
The grenade is grasped with the right hand; the rubber strap (manual sa-
fety) is then pulled off using either the left hand (fig. 10) or the teeth.
Fig. io
The grenade is then launched to 15-20 yards.
The external metal bands and the internal retarding metal strip are releas-
ed during the trajectory. It is only when the metal strip is released that the
two firing pins come into line with the detonators, thereby arming the fuze.
ATTENTION: Whenever the grenade is used in its defensive configuration, the
launcher should be sufficiently protected, as the range of the fragments
is considerable.
2) LAUNCHING OF RIFLE GRENADE
The defensive hand grenade is screwed on the corresponding threaded
housing of the finned tail-cone taking care to keep the rubber strap towards
the finned tail, while the ogive is screwed on the other end.
After having loaded the rifle with the launching round (taken from the tail
cone), the grenade is fitted on the launching tube, with all its safety devices,
including the manual safety device, on. The last is released automatically by
inertia forces as the grenade starts on its trajectory. This prevents any possible
mistakes, renders simpler the use of the grenade and also permits to maintain
all the safety devices on until the grenade is under way. Further, it results in
the possibility — (in case of revoked launch) — of taking down the grenade
from the rifle with no risk whatever, and eventually dismounting the tail cone
and the ogive without any special care.
Fig. П
S.C.M. MOD. 64 GRENADE SPECIFICATIONS
« Offensive » Hand Grenade
Outside diameter	2.05”
Over-all length	3.54”
Weight of metal parts	3.53 oz
Weight of bursting charge	3.53 oz
Weight of detonators-boosters	.35 oz
Gross weight of « offensive » grenade	7.41 oz
« Defensive » Hand Grenade
Outside diameter	2.05”
Over-all length	3.54
Weight of offensive configuration	7.41 oz
Weight of added coils	7.41 oz
Gross weight of « defensive » grenade	14.82 oz
« Rifle » Grenade
Finned tail major dia	2.44”
Over-all length	10.95”
Weight of	defensive configuration	14.82	oz
Weight of	finned tail cone	6.00	oz
Weight of	ogive (plus 770 grains TNt)	2.65	oz
Gross weight of rifle grenade
1 lb 71/2 oz