RIFLE GRENADES
GRENADE LAUNCHERS
Tromboncino [trombonˈtʃiːno]: diminutive of Trombone, but not necessarily the 15th century musical instrument: Trombone in Italian indicates a large Tromba (trumpet).
Tromba derives by the old latin for Tuba, which indicates both the lead tubation and the ancient musical instrument, later modified by German languages into the term Trumba.
The word Trombone was used since the 16th century to indicate handheld bluderbusses, indicating, again, a large tromba-like object, because of their conical shaped muzzle. Then Tromboncino was used to indicate a small blunderbuss.
When flash hiders were introduced as a gun accessory in the late 1800s, they were conical shaped; and, again, looked like a trumpet end, so they got named Tromboncini in Italian terminologies.
When barrel mounted grenade launching tubes were introduced (for the Bertone and Vivien-Bessiere Grenades) they got quickly nicknamed Tromboncino too, especially since the french would do the same, naming the launching tubes for the V-B "Tromblon".
The complete Italian name for these devices would be Tromboncino Lanciagranate, to differentiate it from the Tromboncino Spegnifiamma/Rompifiamma (Flash hider).
FIRST WORLD WAR
- AASEN
- BENAGLIA
- BERTONE
- EXCELSIOR-THEVENOT P3
- VIVIEN-BESSIERE
- PROTOTYPES
INTERWAR PERIOD
- TROMBONCINO MOD.28
- "TERNI" PROTOTYPES
- BREDA PROTOTYPES
SECOND WORLD WAR
- TROMBONCINO MOD.43
- PROTOTYPES
POSTWAR PERIOD
- TROMBONCINO MOD.61
- TROMBONCINO MOD.63
FIRST WORLD WAR
AASEN
In 1906 the Norwegian inventor Nils Waltersen Aasen patented a rather modern and effective hand grenade system. He further developed it and, since the Norwegian government was not interested in the project, he founded his own company in Denmark, under the name Det Aasenske Granatkompani.
This new weapon system was a commercial success, being rapidly adopted by several European nations, including France and Italy in the years immediately preceding the First World War.
Italy in particular adopted both the hand grenade and rifle bomb variants already in 1912, for use during the Italian-Turkish war.
During the First World War, these grenades were reused during the early stages of the conflict, only to be replaced by more modern models introduced in later stages of the war.
What's peculiar about the Italian adoption of this grenade is that it was introduced into service to be fired with a mod.1870 carbine instead of the mod.91 rifle.
In 1915 some of these were modified with a thinner guide rod and a disc at the base of the grenade, useful to perfectly blocking the gas vent at the moment of the shot.
The grenade, having inserted the guide rod into the barrel of the rifle, was projected through the use of special blank cartridges, loaded with 0.475g of solenite for medium distances (green cap, a notch marked on the bottom) or with 1g of solenite for long distance (Yellow cap, two notches marked on the caseback).
The maximum range was about 300 meters, and the trajectory depended greatly on environmental factors (especially any wind).
The grenade was triggered in the air thanks to the propeller placed on the front unscrewing the safety system, and exploded when it hit the ground, projecting 72 cast iron balls within 7 meters.
BENAGLIA
Upon entry into the war, the Italian General Staff quickly realized that trench warfare required greater innovations, especially from the point of view of infantry armament.
Experiments immediately began with a new type of rifle grenade, called Benaglia after its creator.
This consisted of a cast iron casing filled with explosives, with a firing pin activated by impact on the ground. The guide rod at the base of the grenade was inserted into the barrel of the rifle or carbine: a special cartridge was inserted (essentially an ordinary mod.91-95 cartridge without ball, plugged at its neck with a cardboard disc) and the shot was fired, tilting the rifle in the direction and angle indicated by the commanding officer.
Between the summer of 1915, and 1916, when it was formally adopted, several experimental models were developed in succession, each with different primers, cast iron molds, firing pins, loading caps, and stabilizing fins. In particular, the first models had a wooden base to give it an aerodynamic shape, to which several fins of sheet metal were added to stabilize the fall.
There were several variants that remained at the prototype level or were distributed in small batches, the most famous of which were a "Gussi" variant with a sheet metal "skirt" that guaranteed aerodynamics during the fall phase.
At the end of the experiments, the final shape with three fins fixed directly to the steering rod via a nut was adopted, despite a large batch of wooden base grenades was produced nonetheless.
It remained in production and use until the end of the war.
BERTONE
This rifle grenade was adopted in early 1917, inspired by the Vivien-Bessiere. As for the VB, it was fired from a launch tube mounted on the barrel of the rifle or musket, and was operated using ordinary 91-95 cartridges.
Upon firing, the ball passed through the bomb, triggering an ignition capsule. The detonator fuse then had a delay of 9 seconds. After this, the bomb was projected forward by the gases of the shot which followed the ball.
The maximum range was 250 meters with the rifle and 300 meters with the musket, and its splinters could reach a distance of 50 meters when fired. Hastily put into mass production, several issues soon arose, both in terms of manufacturing defects and soldiers reporting serious incidents during its use.
Because of this limited reliability and smaller explosive charge compared to its French counterpart, production was halted in 1917. However, it remained in use until the end of the conflict, and it is still represented in 1919- 1920 army manuals.
Cpt. Emanuele Balbo Bertone di Sambuy
EXCELSIOR-THEVENOT P2/P3
When Italy entered the Great War alongside the Entente powers, it began to receive large quantities of food, weapons, and ammunition.
In particular, Italy obtained various equipment from its French ally, in the form of artillery, machine guns, Saint-Etienne models, and rifles (Lebel and Berthier), especially after Caporetto, but even before some models seeped through.
Among other supplies, France also provided several Excelsior-Thevenot P2 hand grenades, and P3 rifle bombs, along with the information needed to produce them.
The Excelsior-Thevenot bomb was very similar to the grenades developed by Aasen, both in shape and operation. In fact, even the E-T had a propeller on their top which, along the fall trajectory, rotated, unscrewing the safety and allowing the firing pin to be activated upon contact with the ground.
The main difference between the E-T and the Aasen was the presence of a safety pin which held the entire mechanism in place during transport.
The P3 rifle version differed from the hand grenade version in that it had at its base, instead of a wooden handle, a guide rod with a sheet metal tube around it, so as to fit correctly into the rifle barrel and to mantain an aerodynamic shape during flight. This way the bomb could fall on its head, releasing the firing pin upon impact.
Examining various diagrams and instructions reveals another difference between the P2 hand grenade and the P3 rifle grenade.
The P2 had a body (covered in sheet metal) made up of cast iron balls held together by a resinous material, while the P3 had a body (still covered in sheet metal) of cast iron, with the grooves necessary for fragmentation.
Weighing around 400 grams of which 80 grams of "Echo" explosive, it had a maximum range of around 200 meters and had a radius of action of around 20 metres. They were fired with a cartridge with a wooden cap instead of a standard bullet.
There was also a variant of the Excelsior Thevenot that could be fired directly from an independent sheet metal tube with a built-in charge. This disposable device was the version called AF.
VIVIEN-BESSIERE
Created by the French in 1916, it arrived en masse in Italy only after the events of Caporetto, at the beginning of 1918, along with countless other war aid provided by its French ally.
The Vivien-Bessiere functioned similarly to the upstated Bertone shoot-through rifle grenade. It was positioned in a special launching tube placed at the muzzle of the barrel, being fired with an ordinary cartridge.
Upon firing, the ball passed through the bomb, triggering an ignition capsule (H in the drawing) which initiated the detonator fuse, with an 8-second delay. After this, the bomb was projected forward by the gases of the shot which followed the ball.
Weighing approximately 450 grams of which 60 grams of "Cheddite" explosive, it had a maximum range of approximately 180 meters and had a radius of action of around 50 metres.
A conversion adaptable to the mod.91 rifles was tested, but this was not carried forward as the caliber of the ball and the gases released by the mod.91-95 ammunition were often unable to launch the bomb at the desired distances nor to trigger it effectively.
Therefore these grenades were mostly used in the Lebel and Berthier rifles offered as war aid.
PROTOTYPES
BOMBA P.E. PER FANTERIA (PIERSANTELLI)
Prototype we know very little about. Basically, it was an accessory applicable to Mod. 91 rifles, firing a 350-gram, 15 cm long grenade, with 1,000 cast iron splinters per warhead (sic).
The range was approximately 400 meters (at least this is what is reported on the finds in our possession), a very optimistic distance for an artifice of this size.
The grenade was launched through an exploding charge contained in the tube placed behind the grenade, activated by a spring firing pin (operated by hand).
Never went into production
Collezione Taglier, tramite R.Stevanin
INTERWAR PERIOD
TROMBONCINO MOD.28
In the second half of the 1920s, after the experiences gained during the Great War and the "pacification" campaigns in Northern Africa, the Ministry of War issued a request to equip infantry squads with greater direct support during close combat, especially during operations not directly covered by artillery fire.
The requests (based on the designs, patents, and prototypes that have come down to us) for early 1927 trials were as follows:
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The new Tromboncino weapon system had to be mountable on the Mod. 91 TS carbines (or the Mod. 91/24 variant).
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The Tromboncino must not have prevented in any way and at any time the regular use of the carbine, therefore it had to be mounted in a special separate position.
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The Tromboncino had to be capable of projecting an explosive grenade of approximately 40mm in diameter at a distance of at least 200 meters.
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The Tromboncino had to project the grenade using ordinary ball ammunition mod.91/95.
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The Tromboncino had to be operated with the same trigger as the Carbine.
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The tromboncino had to use a 200g grenade, capable of exploding despite the angle of impact and ready to be throwed by hand in case of emergency. To execute this in complete safety, the base request was to use a smoothbore launching tube.
MBT and Breda most likely participated in the tender, along with others. Although we have no certain information/documentation on the matter, it seems that the winning Tromboncino model was the one presented by Terni, formally adopted as the Tromboncino mod.28 (and mostly produced by MBT).
The Tromboncino mod.28, mounted on the left side of the Moschetto mod.91 for TS (modified) through special inlays in the wood, was supported by a metal frame and had the operating mechanism directly connected to the trigger of the Carbine.
It was loaded by inserting a grenade (created specifically for this project, approximately 72mmx38), into the muzzle of the Tromboncino. Then, the bolt was extracted from the musket, a regular bullet cartridge was manually inserted into the bolt face, and the bolt was inserted into the mobile breech of the Tromboncino (which functioned similarly to the carbine's breech). At this point, by pressing the rifle's trigger, the mechanism within the Tromboncino's sear was activated, the firing pin was released, the shot was fired, and the grenade was then projected forward with the gases released by the ammunition.
However, the cartridge bullet was not projected together with the grenade, but was retained in the chamber and expelled together with the exploded cartridge case.
Each 15-soldier infantry squad was therefore equipped with three Tromboncino mod.28 mounting TS carbines.
Within a short time, it was realized that the grenade initially adopted was not particularly effective: in addition to having a rather erratic trajectory, it often did not explode upon contact with the ground, due to the wrong angle or because it did not release the firing pin correctly.
A new type of ammunition, the SR (later SR2), was adopted around 1930. It was produced by the Società Romana Costruzioni Meccaniche.
This new ammunition was approximately 40mm longer (114mmx38), as it housed a 4-fin stabilizer at its base, useful for facilitating the trajectory and ensuring that the projectile fell exactly head-on, activating the firing pin and detonating the grenade correctly.
In order to correctly house the new ammunition, the Tromboncini mod.28 were modified by shortening the grenade retaining peduncle, which thus went from 62.2mm to 23mm.
The concept of the Tromboncino had a very short life, for several reasons:
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The Tromboncino mod. 28 was bulky, unbalanced, fragile, expensive, inconvenient to load and took away the riflemen's ability to fire the carbine while using the Tromboncino.
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The Tromboncino had a very short barrel, so the accuracy was more dependent on chance than on a real study with a maximum range of 200 metres.
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The tromboncino couldn't regulate the gas driven onto the grenade, so the launch was always the same, which could be problematic to make short launches onto enemy trenches, since the trajectory would have been too straight on such short distances.
The Tromboncino mod. 28 already produced were removed from service with the introduction of the mod. 35 "Brixia" light mortar in 45mm, which worked essentially the exact same way, but with a longer barrel, better accuracy, improved explosive charge inside a larger grenade, capable of reaching 500 meters. This was naturally possible because the Brixia 35 did not have to be fired from the shoulder, but was installed on a carriage adequate to manage the recoil and reliability over long distances, managed by a special team.
The 23.000 TS carbines that mounted the Tromboncino mod.28 were dismantled, most of the devices were scrapped and recycled in foundries, while the old stocks, now obsolete, had the empty spaces filled with wooden inlays, and were mainly recycled in other mod. 91 or converted mod.38 carbines.
Courtesy of M. Holmes
"TERNI" PROTOTYPES
TROMBONCINO MOD.28 R
In July 1928 Terni developed this new iteration, with the barrel of the tromboncino and the barrel of the carbine itself pivoting around the center part of the stock, in order to have a single receiver for both devices. Taking back the bolt (the chamber and the bolt lugs were hosted in the barrel itself) and pushing a button you could easily pivot the forward part of the stock around, swapping the main barrel to use.
It kept the same issues of the Mod.28L, so difficult aiming, lack of gas regulator for shorter shots, fragility of the wooden stock.
TROMBONCINO MOD.29 L
While the mod.28 was put hastly into production, and the mod. 28R was developed succesfully, the Terni Arsenal developed a way to update the mod.28 tromboncino already in production, especially for its lack of gas regulation and consequent difficulties in shorter trajectories.
This was obtained by applying a device patented by Ercole Galassini, basically a reinforced dial at the base of the tromboncino to redirect and regulate part of the gas from the cartridge. This never went further than the prototype stage.
TROMBONCINO MOD.29 R
While the Mod.29L update for the mod.28L already in production was developed, the Terni technician proceeded into a whole new project to better implement the Tromboncino concept. This project became the Mod.29R.
So they built a carbine with integral tromboncino, following the previous mod.28R design but with the new mod.29L gas regulator. The project was further updated with the use of a Elektron stock (magnesium/Alluminum) instead of the wooden one: It was a hollowed, stamped/fuse stock, built following Isotta Fraschini's patents for hollow stocks, further employed in Semiauto rifle prototypes.
TROMBONCINO MOD.29 R bis
The mod.29R project had its own limits of bulkiness and grenade launching capabilities, so it was further developed into the mod.29R Bis, with the Elektron forward part of the stock enveloping the receivers and had an integral mannlicher magazine, working exactly as the standard mod.91 magazine.
The Tromboncino was reduced and the gas regulation device was detached from the grenade launching barrel itself, becoming an independent rotating ring. This helped especially with heat mitigation issued that rosed with the previous gas regulating device.
Grenade development
During the 1929-1930 developments, the Technical office dropped the idea of using the grenade for the tromboncino also as a hand held grenade in case of emergency.
Hence, they had the chance to increase the weight of the grenade itself (up to 350g at first) and the possibility of using it in a rifled barrel. The latter wasn't implemented in a conventional way, with a round barrel with grooves, but instead it was developed in a shaped exagonal barrel and a correspondant exagonal shaped grenade.
Said grenade was developed in two versions, a 350g and a 500g one. The explosive potential was far more increased and with it the effectiveness of the grenade, with the "rifling" increasing its precision and accuracy on the target, further helped with the gas regulation device to help finding the perfect angle for the trajectory.
Having the grenade projected to fall always perpendicular to the ground also helped in further semplifications (just a mere percussion cap/fuze on the top) and even more space for the exploding charge.
TROMBONCINO MOD.30 R
The final iteration offered by Terni (hence concluding its stuies on the Tromboncino) was the Mod. 30 R.
This iteration was basically the unification of all previously experimented improvements, with the final updates on "rifled" grenade launching barrel, an integrated sighting system and a more ergonomical stock for shoulder firing.
It was produced in two different versions, one to fire a 350g grenade up to 650 meters and one to fire a 500g grenade up to 550 meters.
TROMBONCINO MOD.32 R
A further improvement of the mod.30R, nomenclature is unofficial but it was built with a 1932 Moschetto Barrel. It shows several structural improvements to its previous iteration.
BREDA PROTOTYPES
In the second half of the 1920s, the Ernesto Breda company developed and patented several prototypes of rifle grenades and Tromboncinos, probably to take part in the Ministry of War tender which would end with the adoption of the Tromboncino mod. 28.
The photos of the prototypes that have come down to us demonstrate a clear interest in equipping Mod. 91 weapons such as the TS and the 91/24 with a rifle grenade launcher. Later models, however, experimented with designs likely intended for the foreign market.
On October 7th 1927, a special rifle grenade with a removable safety and deformable cap was patented, capable of triggering the firing pin even from different impact angles, as requested in the 1927 directives from the Italian high command.
Tromboncino per Moschetti mod. 1927
On November 22nd 1927, Breda patented a muzzle-mounted grenade launcher applicable to rifles and carbines mod. 91. It featured a helical groove capable of diverting the cartridge's vent gases (after the passage of the bullet), directing them towards a second expansion chamber containing the grenade to be thrown.
The carbine would have this Tromboncino attached to the muzzle and held firmly in position by a hook that was engaged on the bayonet lug; in this configuration it could fire ordinary bullets and possibly launch explosive devices. The quantity of gas that actually passed into the expansion chamber could be adjusted using a special crank positioned on the left side of the device.
Since this tromboncino perfectly reflects the specifications used by the Tromboncino mod. 28 (musket usable at any time, grenade propelled by ordinary ammunition, etc.) it is very likely that it was developed in competition with the one that will be adopted as the Tromboncino mod.28, but probaby refused for its bulkiness, cost or weird mechanism.
Tromboncino sperimentale Mod. 1929 A
On August 12th 1929, therefore after the Italian army's formal adoption of the Mod. 28 Tromboncino, the Ernesto Breda Company patented a new grenade launcher, this time to be mounted on specially built weapons. The drawings show that the accessory was designed to be installed on Mod. 91 weapons, likely in anticipation of future requests from the Ministry of War.
The photos of prototypes that have come down to us, however, depict the use of Mannlicher-Schonauer carbines, probably leftovers from the weapons contract Y1903/14/27 built by Breda for the Greek government in that period.
The mechanism in question worked on specially prepared weapons, with a barrel completely separate from the cartridge chamber, in such a way as to completely envelop the firing gases, directing them as best as possible towards the expansion chamber where the bomb to be launched was present.
The Tromboncino grenade launcher, in this version, was integral with the barrel, the chamber and the body of the weapon itself, as can be seen in the technical drawing.
The barrel, screwed onto the Tromboncino's weapon system, could be screwed more or less tightly towards the rifle chamber to increase or decrease the volume of gases directed into the expansion chamber.
The front sight during the screwing of the barrel did not undergo any changes, as it was integral with the Tromboncino and not mounted on the barrel itself.
Tromboncino sperimentale Mod. 1929 A
On August 12th 1929, therefore after the Italian army's formal adoption of the Mod. 28 Tromboncino, the Ernesto Breda Company patented a new grenade launcher, this time to be mounted on specially built weapons. The drawings show that the accessory was designed to be installed on Mod. 91 weapons, likely in anticipation of future requests from the Ministry of War.
The photos of prototypes that have come down to us, however, depict the use of Mannlicher-Schonauer carbines, probably leftovers from the weapons contract Y1903/14/27 built by Breda for the Greek government in that period.
The mechanism in question worked on specially prepared weapons, with a barrel completely separate from the cartridge chamber, in such a way as to completely envelop the firing gases, directing them as best as possible towards the expansion chamber where the bomb to be launched was present.
The Tromboncino grenade launcher, in this version, was integral with the barrel, the chamber and the body of the weapon itself, as can be seen in the technical drawing.
The barrel, screwed onto the Tromboncino's weapon system, could be screwed more or less tightly towards the rifle chamber to increase or decrease the volume of gases directed into the expansion chamber.
The front sight during the screwing of the barrel did not undergo any changes, as it was integral with the Tromboncino and not mounted on the barrel itself.
Tromboncino sperimentale mod. 1929B
On December 30th 1929 the Ernesto Breda Company patented a further development of its previous system, in which the cartridge vent gases could be cut off by the use of a lateral "crank", which could completely or partially seal the vent of gases directed to the chamber expansion of the grenade when needed, and thus allowing greater exploitation of the gases for firing the standard rifle bullet.
Tromboncino sperimentale mod. 1933
On 14 July 1933, the Breda Company patented a further development of its previous Tromboncino mod.27. This new design, intended for export, as evidenced by pictures and prototypes showing its use with a Mauser 98 type rifle, was usable with rifles and carbines.
The substantial difference compared to the previous mod.1927 model is that the gas regulation is linked to an aiming system, with which the necessary range can be directly calculated, based on the inclination given to the rifle during aiming.
SECOND WORLD WAR
TROMBONCINO MOD.43
Between the end of 1942 and the beginning of 1943, as the strategic picture in the Mediterranean became more complicated for the Axis forces, the German High Command began to collaborate more closely with the Italian logistical-military-industrial system.
This period saw a flourishing of technological collaborations between the two industrial forces, most notably the adoption of the K98/MP40 style musket slings, the adoption of the K98 rifle with scope for sharpshooter units (manual dated April 1943), and the adoption of the Tromboncino mod.43.
The Tromboncino mod.43 was essentially a licensed copy of the German Gewehrgranatgerät/Schiessbecher, modified for the size of the 91: it was mounted around the sight of the TS musket, resting it on the muzzle and securing it in position with the clamp placed at its rear.
Having 30mm in diameter, it had 8 right-handed grooves.
It could fire the same grenades developed for the German model, propelled by the explosion of a mod. 91/95 cartridge without bullet, closed at the collar with a cardboard disc, glued with lacquer. Subsequently, cartridges crimped to the tip would be used. The cartridge charge in 6.5x52 was approximately 2 grams of ballistite (some sources report 2g of black powder).
Several examples appear to have been produced by F.N.A..
PROTOTYPES
LANCIABOMBE CONTROCARRO SPERIMENTALE
EXPERIMENTAL ANTI-TANK GRENADE THROWER
Developed by the Army Technical Office (Direzione Superiore del Servizio Tecnico d’Artiglieria) in the first half of 1943, this weapon was essentially the fusion between a Carcano carbine and a 60mm mortar.
This weapon, weighing 7.8 kg, was capable of firing an 850 gram hollow point grenade at a distance of 80 meters in direct fire and 250 meters in arc fire.
The hollow-point bomb had an explosive charge of 370 grams of T4 (trimethylenitroamine), and was capable of piercing a composite steel armor 70mm thick (one steel layer of 30 and one of 40mm).
The bomb was propelled by a 6.5x52 blank projectile, crimped to the collar. The blank projectile regularly exploded in the carbine's chamber, and the gases from the explosion were conveyed into an expansion chamber, to then be redirected to the base of the bomb, which was thus propelled forward, reaching a speed of 60 m/s.
The designer hid the plans and prototype of this weapon after September 8th 1943 to prevent it from falling into the hands of German forces.
When the Allied forces liberated Rome in June 1944, the designer took the plans and prototype to US Army headquarters (Section G-2), where the weapon was inspected.
The prototype and documents may have then been brought to the United States, where they were possibly locked up in one of the many US Army warehouses.
POSTWAR PERIOD
TROMBONCINO MOD.61
This device was the evolution of the Tromboncino mod. 43: it retains the same muzzle attachment for the TS muskets and the same annular enlargement at the base. A smooth-core barrel extension with ribs, with a diameter of 22mm, was screwed onto this annular enlargement.
It was developed for public order service, so that all the grenades used by the army and the Carabinieri forces through the BM59 could be used.
The Italian Police (Guardie di Pubblica Sicurezza) had at their disposal:
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Artifizio Lacrimogeno NL CS/M1 - Chloroacetophenone Tear Gas
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Artifizio unificato mod.60 - Smokescreen bomb
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SCM mod.64 - Anti-personnel bomb
The tromboncino mod.61, like its equivalent for the BM59, was not a bomb launcher cup, but rather an extension of the barrel (with an external diameter of 22mm) where the device to be launched was directly inserted; the latter was held in position by a wire spring.
To use it, the tail of the grenade was inserted over the tromboncino, then the appropriate 6.5x52 blank cartridge (crimped at the collar) was loaded into the carbine , the action was closed, the weapon was pointed in the desired direction (in public order operations the order was to aim towards the asphalt of the road surface) and the shot was fired. The gases from cartridge thus projected the grenade forward.
POSTWAR PERIOD
TROMBONCINO MOD.63
The Tromboncino Mod. 63 is the evolution and replacement of the Mod. 61.
It differs from its predecessor only in the lack of the annular enlargement at its base.
Thus, the Mod. 63 was essentially a new production, no longer a simple adaptation of the Mod. 43.
It became the standard grenade launcher used by the Italian Police during most of the street clashes from the 1960s to the early 2000s.
