Like all other modern militaries participating in World War 2, the Italian Army adopted a light infantry mortar to provide indirect fire support against enemy positions at the platoon level. The "Brixia Model 35" was based around a 45mm light fragmentation projectile weighing 16.4 ounces and able to reach target areas out to 580 yards in ideal conditions. Its design was somewhat unconventional for the time, featuring a folding steel tripod mounting affixed to the launch tube. The structure offered the needed recoil support when firing the weapon and integrated elevation and traverse controls for normal function. The launch tube itself sat between the forward legs of the tripod with the remaining leg facing the rear. A padded seat was attached to a frame, this being attached to the rear leg, to allow the firer to sit somewhat comfortably (or lie prone) behind the weapon when operating it (the padded frame doubled as a back support cushion for a carrier when the unit was in transit). The end result was a somewhat effective, overambitious mortar design that suffered from its inherent complexity leading to high procurement costs and slow production. As the system did not break down neatly like her contemporaries, the weapon also proved heavy and cumbersome on the march. The mortar was adopted for service in October of 1935 and bestowed the apt-designation of "Mortaio d'assalto 45/5 Brixia, Modello 35". The "45/5" identifier was in regards to the caliber (45mm) and the length of the barrel (5 x 45mm). In reality, the barrel measured slightly longer at 262mm.
One of the key limitations of the Italian 45mm light mortar was its use of the 1.8-inch projectile, a shell even smaller than the one used by the British in their 2-inch light infantry mortars. The projectile was of steel fragmentation design which was detonated on impact and showered the target area with lethal steel fragments. While effective at ground zero, the actual range of the fragments was severely limited in part to its lightweight design and low charge. Each projectile was loaded from the breech of the launch tube as opposed to the muzzle, a drastic departure from other mortars of the period. Additionally, the charge was applied as a separate portion of the firing phase, they being fed from a 10-round magazine attached to the weapon. Firing was actuated through a "trigger" style facility.
The entire firing action consisted of inserting the 10-round charge magazine into the provided well at the top-rear of the launch tube. The operator then manually-armed the projectile, opened the breech via a knobbed lever moved forwards and inserting the projectile into the open trough. When the lever was brought down, the charge was activated which forced the projectile from the barrel. The operator need only to arm and insert a fresh projectile into the breech and managed the trigger handle for successive shots until the charge and ammunition supply were all spent.
As a complete system, the Model 35 offered Italian Army mortar teams a strong repeat-fire presence on the battlefield. A trained and experienced crew could fire between 8 and 10 rounds per minute with teams reportedly having reached up to 18 or 20 in the heat-of-battle. This sort of suppressive fire proved critical to the infantry advance and the Italian design did not disappoint in that respect. Elevation spanned from +10 to +90 meaning that the launch tube could be lowered and utilized as an ad hoc field gun when pressed. However, its low-velocity shell certainly limited its use against true armored vehicles of any type. Traversal was limited to +20 to either side. Due to the "single-charge" approach in the Model 35's design, ranging was handled through a "open-close" vent feature to which ports were managed - closed ports allowed the full 580 yards to be reached while open ports allowed for targeting of areas within 350 yards, the latter effectively serving to reduce the base charge propellant.
As a complete system, the Model 35 weighed in at 34lbs which made it man-portable on the battlefield between two personnel though assisted by a pack animal when possible. The standard operating crew was, in fact, two and this arrangement allowed one soldier to handle elevation and traverse controls as well as firing while the other handled the ammunition stores and reloading. Ammunition was only limited by the supply on hand though usually consisting of a box of ten.
Despite the limitations in the Model 35 design, the weapon persisted in Italian ranks for the duration of the war fighting wherever the Italian Army found itself against an enemy. Italian war industry was not arranged in such a way as to fully design, develop and manufacture a better solution in the time allowed so the Model 35 soldiered on - this is not to say that the weapon did not provide some battlefield value for it did. German shortages in North Africa also led to use of the Model 35 for the interim under the designation of "4.5cm Granatwerfer 176(i)" - the "i" signifying their Italian origin. There were even operating manuals printing in German due to the large-scale use of the weapon in German hands. It was also not uncommon for Italian partisan units to commandeer ex-Army Model 35s for use against Axis-aligned forces, particularly after the Italian defeat in September of 1943. Model 35 mortars served alongside the Model 35 81mm version, the Italian copy of the hugely successful British "Stokes" / French "Brandt" designs.
Model 35 mortars were fielded in Italian Army service up until 1950.