Categories
WW2 Italian AT Weapon

65mm L.17 Mountain Gun

Italy ww2 Kingdom of Italy (1902-1945)
Mountain Gun/Anti-tank Gun – 1,146 Built

Fighting in mountains poses some unique problems for an army. Most crucial amongst these problems is firepower. How do you bring firepower into areas which may only be accessible by rope line? This question is the basis of the mountain gun, a compact weapon able to deliver shells against an enemy force and which can be broken down for transport in multiple loads.

65mm L.17 Model 1913 Mountain gun. Source: Italian Ministry of Defence

Development

Work on a gun to meet the extreme needs of fighting in mountainous terrain began in Italy as far back as 1902 at the Turin Arsenal. This was to be the first gun developed and built completely within Italy for the modern army. The barrel was all steel and, unlike older guns which had to roll back to cope with recoil, this gun had a built-in recoil mechanism. The breech was an interrupted screw type breech.

This design was at the cutting edge of technology when it was conceived and first outlined back in 1902. However, by the time it actually received production orders in 1911, it was still a good gun but not the most modern piece available. Its largest flaw was the lack of elevation, just +20 degrees, meaning that for firing at high elevations troops would have to back the gun onto a ramp. This expedient measure meant that this gun was also envisioned as serving an anti-aircraft role too, though its effectiveness in this role even in WW1 is dubious at best.

Design

The requirements for a mountain gun include that it can be broken down for movement. The 65/17 had a steel barrel on a steel frame with a single fixed tail and carried on wooden spoked wheels with a steel rim. It could be broken into at least 5 (some say 6 pieces – probably due to the optional shield for the gun) for transport by pack mule. In this way, the gun could be towed on a wheeled trailer or pack carried. Ammunition was also pack carried being moved in wooden crates, 2 shells to a box. The gun was light enough to be towed by pack mule, small tracked tractors like the Fiat OCI 708M, motorised tricycles, or even by the soldiers themselves.

Service in Word War 1

Production, like development, was slow. Orders placed in 1911 for this 1902 designed gun were not delivered until 1913. By May 1915, when Italy entered WW1, just 212 guns had been produced. By the end of the fighting in November 1918 a further 685 had been made by both the Turin Arsenal and Naples Army Arsenal, but due to wartime losses the total inventory remaining at the end of WW1 was just 523 guns.

Post WW1

By 1920, the gun was obviously out of date. Despite its good points, the 65 mm gun was insufficient for the needs of the Army and it was replaced by adopting the Skoda 70 mm L13 mountain gun. The Italians had captured large numbers of these guns as Preda Bellica (P.B.). The 65/17 did not disappear from service because of this replacement.

In 1925, an experimental version was trialed with rubber tyres instead of the older wooden and steel ones. The gun shield was smaller and a small limber was available too. In 1926, it was officially reassigned to Infantry units from mountain troops at a rate of 3 guns per regiment and later at 4 guns per regiment.

The colonial troubles in what is now Libya were the next war for the 65/17. Several batteries of guns were sent to fight the insurgency there and, for the first time, the gun was carried on a wheeled vehicle, a Fiat 15ter truck. The gun had already been mounted on tracked vehicles, such as the Fiat 2000, and considered for other vehicles, but this was the first ‘portee’ mounting.
The gun also saw combat in the next Italian war, the war in Ethiopia, and in the Spanish Civil War.

During the Spanish Civil War, in 1936, Italian forces brought with them some 343 guns, some of which were issued to Spanish Nationalist forces. It was during this war that the 65/17 saw its first use as a anti-tank weapon. The relatively weak armor of enemy tanks, like the Soviet supplied T-26, meant that, even with the relatively low muzzle velocity and lack of dedicated anti-tank ammunition, the 65/17 was still an effective anti-tank gun.

Those 343 guns constituted more than half of the available 65/17 guns in Italian inventory but, just as it had been replaced in 1920 for mountain work by the Skoda 70/13, it was replaced in 1935 in infantry use by the Ansaldo 47 mm L32 cannon.

Remaining 65/17 guns were reissued to Guardia alla Frontiera (GaF) and Milizia Volontaria per la Sicurezza Nazionale (MVSN) units and some were even fitted to fixed fortifications. Ammunition was available in large numbers so the guns would always have some use. So much so, in fact, that, despite official replacement and because of losses (either from combat or simple wear and tear) in the Ethiopian and Spanish campaigns, production was actually resumed in 1937, producing 249 new guns.

Despite this reissue and replacement, by 1940 when Italy entered WW2, some regiments were still equipped with this gun.

65/17 dug into a well protected pit in North Africa. This example has the large gun shield fitted. Source: unknown
Captured Morris CS8 with 65/17 fitted in use by Italian forces in Tunisia. Source: Riccio

World War 2

Immediately prior to the Italian entry into WW2, the 65/17 was still in front line infantry service. Some guns had the old wooden wheels with steel rims replaced in 1939 with wheels made from Elekton (Magnesium) fitting with rubber tyres as a weight saving and mobility enhancing measure. By April 1940, just before the declaration of War by Mussolini, there were 700 65/17 guns of various states of repair and upgrade in service with Italian forces. There was still a shortage of anti-tank ammunition however.

As the guns and ammunition (albeit not AT ammunition) was plentiful, it is no surprise that it saw extensive use in WW2 on all of the fronts on which Italy fought. In North Africa, the gun was mounted on Fiat 634 trucks as well as on captured British Morris CS8 trucks forming ‘batterie volanti’ (flying batteries). Mounted on a truck bed, these guns were far more useful than on their old carriages, as they could rotate a full 360 degrees. A total of 28 guns were mounted in this way in 7 batteries of 4.

65/17 gun belonging to the Spezia airborne division in Tunisia being towed by the Guzzi Trialice. Source: Riccio

In Tunisia, the guns saw service with the Spezia airborne division, where they were towed by the Guzzi Trialce (motor-tricycle) formed into 2 batteries of 4 guns. By December 1942, just 444 guns were left in service with the Italians, including those in fixed fortifications. The gun was still in service after the September 1943 armistice too with all parties from partisans to the Germans using them and eight guns being surrendered to the Free French forces in Corsica.

Partisans in a staged photo using a 65/17 with shield in April 1945. Source: Riccio

Ammunition

The 65/17 used a 65mm x 172R round, approximately 4.23 kg in weight. Originally only high explosive ammunition was available for the gun, but was later supplemented with a shrapnel shell and canister shell.

In 1936, an armor piercing (AP) shell (4.23 kg) was produced for the gun but was always in short supply. The gun, despite being completely out of date by 1942, was still in common use and a shaped charge ‘EP’ (effetto pronto – rapid effect) shell was developed which was capable of penetrating up to 120 mm of armor. The range was limited to 6.5 km for HE and 500 meters for AP shells. The rate of fire was between 6 and 12 rounds per minute.

65 mm shells for the 65/17. Left to right: High Explosive, Armor Piercing, EP ‘Effetto Pronto’ (hollow charge), and EPS ‘Effetto Pronto Speciale’ (hollow charge). Source: US Military Intelligence

Conclusion

The 65/17 saw service from 1913 until at least 1945 on all fronts. It fulfilled the role of a mountain gun, infantry gun, tank gun, anti-aircraft gun, anti-tank gun and even a dirigible mounted gun. Ironically the gun was designed for use in terrain and saw its most famous work while mounted expediently onto vehicles for fighting in the mostly flat deserts of North Africa.



Illustration of the 65mm L.17 Mountain Gun produced by Andrie Kirushkin, funded by our Patreon Campaign.

Specifications

Calibre 65mm
Lenght 3.57m overall, barrel 1.15m
Width 1m
Height 1.25m
Weight 556kg
Elevation -7 (also given as -10) to +20
Traverse (on normal mount) 8 degrees
Muzzle velocity 320-355m/s
Range 6.5km (HE), 0.5km (AT)
Ammunition HE, Shrapnel, Canister, AP, EP, EPS
Anti-Armor performance 76mm to 120mm

Sources

Italie1939-45.com
Italian Artillery of WWII, Ralph Riccio
Iron Arm: The Mechanization of Mussolini’s Army, 1920-1940, John Sweet
Gli Autoveicoli da Combattimento Dell’Esercito Italiano V.2, Pignato and Cappellano
TM 9-1985-6 and TO 39B-1A-8 “Italian and French Explosive Ordnance” US Military March 1953
Light Fieldguns, Franz Kosar
Italian Armoured Vehicles of World War Two, Nicola Pignato
La Meccanizzazione dell’Esercito Italiano, Ceva and Curami
motoguzzi.com


Categories
AT weapons WW2 Italian AT Weapon

60mm Lanciabombe

Italian armour ww2 Kingdom of Italy (1943-45)
Experimental Anti-Tank Weapon – 1 Built

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Sketch plan of prototype anti-tank weapon. Source: Report 311

Desperate Times

When nations have their backs against the wall and are facing a fight for their existence, there tends to be an abundance of rather unusual weapons. Some of the weapons developed by the Home Guard in Great Britain in the Second World War, like the Northover projector, are good examples of this. Italy, with a long tradition of firearms manufacture, was no different and already had extensive experience with grenade firing and small mortars. In 1943 though, their mainland had been invaded by the Allies as they had already lost control of the island of Sicily. Tank production was in a poor state and the Allies’ superiority with tanks left a very bleak outlook for the Kingdom of Italy in the War. An expedient anti-tank weapon was called for.
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Carcano Model 91/24 T.S. The exact variant used is not known. Source: candrsenal.com

Development

The call for this expedient and simple anti-tank weapon came from the Ministry for War prior to the armistice of the 8th September 1943. It was to combine parts from a mortar and a carbine fitted together to form a rather crude, very large caliber gun firing a shaped charge shell. The Italians had already produced a production model carbine with an attached grenade launcher which used a bullet capture system as far back as 1928. This was along very similar lines to the new requested weapon and may have served as some of the inspiration behind it. The Technical Section of the Ministry for War had already made some preliminary experiments prior to September 1943 and the results were promising.
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Model 1928 Tromboncino grenade launcher (both with bolt in carbine and with bolt in grenade launcher) based on the Model 91/28 carbine. Source: modernfirearms.net
The weapon was given the go-ahead but, by the time of the armistice, only a single experimental prototype had actually been constructed, although performance trials were underway by September 1943.
With just this one prototype constructed by the time of the armistice, the unidentified Italian officer in charge of the project hid the weapon and all of the paperwork associated with it, to prevent it from falling into the hands of the Germans.
When the Allies entered Rome in June 1944 this hidden secret weapon and associated paperwork was removed from its hiding place and taken by the Italian officer to the US Army G-2 Headquarters in Rome (APO 794).
The weapon was examined by Major Russell Fisher and the design was closely discussed between him and the Italian officer who even offered to demonstrate the weapon, as he claimed to have fired the weapon many times, from a standing position without difficulty. This offer though was not carried out.
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Compact CEMSA 63.5mm L25.5 mortar which may have been the origin of the barrel. This weapon could throw a 2kg shell well over 300m. Source: CEMSA

Design of the Weapon

The experimental model was, like most prototypes, rather crude. It was made by means of a redundant 60mm mortar tube and a cut down stock from a carbine fastened together. The 60mm shell was propelled from the barrel by means of a black powder cartridge inserted into the breech of the carbine under the barrel.
The drawings do not appear to show any variation from the original magazine or firing mechanism of the Model 91 rifle and therefore it is believed it would use the same 6.5x52mm cartridge.
Upon a pull of the trigger, this blank round was fired in the manner of a normal bullet except that the explosive gases upon leaving the very short barrel, instead of propelling a bullet, were directed into a large expansion chamber under the mortar barrel and then directed to the mortar round. Just like the smaller Brixia mortar, this weapon was fired by means of a magazine fed blank cartridge and a rapid rate of fire would be able to be obtained. Reloading would be by the simple means of putting a new shell into the barrel at the muzzle and then cycling the bolt action of the rifle to chamber a new blank cartridge. The rifle had a six-round clip inside and, assuming these blank rounds simply replaced the old live rounds, only shells would have to be loaded for the first six rounds.

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Rifle calibre blank cartridge containing the 1.9 grams of ballistite propellant. Source: Report 311

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Example of the type of blank initiator round used. This example is for the 45mm Brixia mortar. Source: not known

Propulsion System

The expanding gasses released from the combustion of the 1.9 grams of ballistite in the blank cartridge were directed into the expansion chamber. This chamber was connected by two short barrels backward (towards the firer) and into the breach of the 60mm mortar tube. This unusual mechanism had the disadvantage that not all of the propulsive force of the black powder charge was directed to the mortar round. A lot of energy was lost. It had a significant advantage, however, that the pressure rise in the barrel was very even, permitting a consistent rise in pressure for the propulsion of the shell. The interview with the Italian officer yielded information that, over the course of its short development, various expansion chamber sizes were tested out in order to achieve the required balance in the pressure gradient within the weapon.

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Detail of gas porting system to move gas from expansion chamber to the rear of the barrel. Source: Report 311


Illustration of the 60mm Lanciabombe by Andrei “Octo” Kirushkin and paid for with funds from our Patreon campaign.

Recoil Management

Recoil was managed in two ways. The first was a very simple spring loaded mechanism in the buttstock of the weapon cushioning the shoulder of the firer. The second part of the recoil management was more complicated, far too complicated for a weapon meant to be an expedient design. This system consisted of a slide onto which the main barrel was mounted. This slide permitted the barrel to move backward and this motion was dampened by means of a spring.
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Details of sprung shoulder pad as part of recoil management. Source: Report 311

The Shell

The shell itself was very similar to the rather small 45mm Brixia mortar shell and was a short shell just under 30cm long with a rounded nose. The explosive body containing the charge was attached to an aluminum tail section with eight fins approximately 12cm long. This 60mm round weighed just 0.85kg and contained 370 grams of T4 (trimethyl trinitro amine). The explosives were arranged around an inner cone made from steel and a hollow front section. The rounded nose was a simple cap made from steel. The charge was detonated upon striking a hard target by means of an instantaneous fuze in the base of the projectile. This was the same type of fuze used in the Brixia mortar, although work on an armor-piercing shell for the Brixia was discontinued by 1941. The fuze would therefore almost certainly be of an all-aluminum construction like the Brixia M.1939 fuze.
The propelling gases could throw this small shell accurately out to a range of 80 meters in a flat trajectory and when fired in a high arc a maximum bombarding range of 250 meters. Armor penetration was by means of the shaped charge and was found to be able to defeat up to 70mm of armor on a test target consisting of plates of 30 and 40mm thick armor.
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60mm hollow charge shell. Source: Report 311

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60mm HEAT round for the weapon. Source: Modified by author to illustrate explosive filler

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Cross section of the 45mm Brixia shell showing fize system. Source: US Military Manual of enemy ammunition

Conclusion

The weapon never reached production status and the war had already progressed well past the point where even if it had been in mass production it would have made any effective difference. The war for the Axis was lost and this weapon was just one of innumerable lost prototypes and projects. It had no effect on the war but was a novel solution to the problem of a shoulder-fired anti-tank weapon. The current location of this weapon handed to the Americans in 1944 is not known.
Specifications:
Calibre: 60mm
Length:
Weight: 7.8kg (unloaded)
Weight of shell: 0.85kg
Weight of explosives: 0.37kg
Anti-armor performance: 70mm
Range: up to 250 meters
Muzzle velocity: 60m/s

Links, Resources & Further Reading

Report 311 ‘Italian Anti-Tank Shoulder Weapon’, Major R. Fisher, US Army, Department of Commerce, 5th December 1944
Andare Contro i Carri Armati, Cappellano and Pignato
https://candrsenal.com
CEMSA 63.5mm Mortar Manual
War Office Pamphlet No.4 Handbook of Enemy Ammunition 1940
Unnamed US Military Manual on enemy ammunition circa 1942
Modern Firearms.net https://modernfirearms.net/en/grenade-launchers/italy-grenade-launchers/tromboncino-m28-eng/

Forgotten Weapons video of the Modello 1928 Tromboncino Grenade Launcher