In action the Böhler anti-tank gun was often used with the wheels removed and with the forward part of the carriage resting on a firing platform. A periscope sigh t was used, even for anti-tank use, and no shield was usually fitted. The gun could be broken down into loads for pack transport on mules.
The little Bonier 4.7-cm (1.85-in) antitank gun was first produced in 1935, and is thus sometimes known as the Model 35. It was first produced in Austria but its use soon spread outside that nation and licences to produce the gun were taken up by Italy. In fact the Italian production run reached the point where the Böhler gun became regarded almost as an indigenous Italian weapon, the Cannone da 47/32 M35.
The Böhler gun was a handy weapon that was soon diverted into other roles. It was widely issued as an infantry gun and as it could be rapidly broken down into a number of pack loads it was also employed as a mountain gun. But though as it turned out the Böhler was something of a multipurpose weapon, it was not entirely successful in any of these extra roles. It did prove to be a fairly effective antitank gun, however, and was widely used during the early war years by a number of nations. Italy was the main user, but others were employed by the Netherlands (Kanon van 4.7), and Romania, and the type also turned up in the Soviet Union (in relatively small quantities) as the M35B. Some also found their way into German army service when Austria came under German domination after 1938, receiving the designation 4.7-cm Pak.
There were several developments on the basic Böhler theme that issued from the company's Kapfenberg works. Although the basic gun remained unchanged, there were numerous variations on such things as types of carriage wheel, the width of the carriage axle and so on. Some models had muzzle brakes while others did not. All models had a feature whereby the wheels could be removed and the gun then rested on the trail legs and a small platform under the axle for firing. This gave the gun a lower silhouette for firing and concealment. The gun could fire both armour piercing and high explosive projectiles, the latter having a range of 7000 m (7,655 yards) to provide the gun with a useful infantry support role. As the armour thicknesses of tanks increased the Böhler increasingly assumed this infantry support role.
There was one odd side-line to the story of the Böhler that is still little known. In 1942 the Allied armies in North Africa were still relatively short of many weapons and the large numbers of captured Italian Böhler guns were a useful windfall. About 100 were refurbished at a Captured Weapons Depot in Alexandria and issued to various units for second-line service. But perhaps the oddest item in this story was that 96 were actually converted by the British for use by airborne forces: the fire-control system of the original gun was altered so that one man (instead of the original two) could lay the gun, and the carriage was modified to allow dropping by parachute; a rifle telescope for aiming and a shoulder pad from a 6-pdr gun were also added. These were, according to the records, issued for service where they proved Very popular'. Unfortunately it has not yet been possible to trace the units involved, but these Böhler guns must have been the very first guns adopted for the airborne role.
Cannone da 47/32 M35
Calibre: 47 mm (1.85 in)
Length of barrel: 1.68 m (5 ft 6 in)
Length of bore: 1.525 m (5 ft)
Length of rifling: 1.33 m (4 ft 4.3 in)
Weight: travelling 315 kg (694.5 lb) and in action 277 kg (610.6 lb)
Muzzle velocity: AP 630 m (2,067 ft) per second and HE 250 m (820 ft) per second
Maximum range: HE 7000 m (7,655 yards)
Projectile weight: AP 1.44 kg (3.175 lb) and HE 2.37 kg (5.225 lb)
Armour penetration: 43 mm (1.7 in) at 500 m (550 yards)