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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