Specifications

With the onset of World War II, the Swiss Army saw a need for a light tank. They purchased some Panzer 38(t) tanks from Czechoslovakia that were armed with 20mm cannons. The Swiss decided that the armament was not powerful enough, so they chose a cannon that fired the 24x138mm round–the Tb 41. Swiss company Waffenfabrik Bern built the cannon, and its design was overseen by Colonel Adolf Furrer, former director of the arms factory at Bern. Furrer had designed the Leichtes Maschinengewehr Modell 1925 (Lmg 25), a toggle-lock action light machine gun, in the 1920s, and he patterned the Tb 41 after that weapon. The action was sometimes referred to as a “Luger” or “Maxim” action; however, it was quite a bit different. His action consists of three arms, as opposed to the Luger’s two. These arms were interconnected by rotating pivots. Recoil would drive the bolt backwards, folding the arms against the recoil spring. The spring would drive the arms forward, moving the bolt into the breech.

It was later decided that the Tb 41 could be used against light armor and lightly protected trucks, so it was modified for use by the infantry. The infantry weapon was fed by a six-round magazine that inserted on the right side, with ejection on the left. When the sixth round was chambered, the magazine was automatically ejected. When the last round fired, the bolt locked open so that a fresh magazine could be immediately inserted. Some Tb 41 guns were installed on tanks, and the gun was rotated 90 degrees so it could be fed from the top. Some were mounted on a tripod and used in fortified positions.

The Tb 41 was designed as a semiautomatic to enable it to put a lot of rounds downrange in a short time. The thinking was that an enemy tank could be disabled if it were hit enough times by the 24mm bullets. As the War progressed, and heavier, better armed tanks were developed, the Tb 41 was relegated to use against light vehicle and armored cars.

It took seven men to operate the Tb 41. Ammo loadout was normally 160 rounds of which 40 were explosive, and the rest were armor-piercing. When used in the field, the gun was transported on a single-axle, wheeled cart by anything from a bicycle to a car. It could even be moved by two soldiers if the need arose. The wheeled cart could be turned into a mount by removing the wheels and rotating the axles into an upright position.

It was possible to remove the gun from its mount and fire it simply by laying it on the ground. This author imagines recoil was somewhat interesting. It did have a rather sophisticated muzzle brake that consisted of eight rings held in a sleeve. Five of the rings had grooves to direct the combustion gas out to the side and rear. The remaining three rings had no gas grooves. By changing the rings, recoil and weapon function could be altered.

Sights were either iron sights similar to the ones found on a Schmidt–Rubin rifle or a 2.2x periscope-shaped optic. The range was said to be up to 1500 yards, but 300 yards is much more likely. Two types of ammunition were available: the armor-piercing Pz-G.V. and the explosive St-G.

The Tankbüchse 41 was the Swiss Army’s first mass anti-tank weapon; although the Tb 41 was never used in combat. Technically, the Tankbüchse 41 was an intermediate anti-tank weapon, but it was not an actual full-on, anti-tank cannon.

24x138mm, Ammunition

The armor-piercing 24mm Pz-G.V. and explosive St-G were created for the new anti-tank rifle. Both of these shells weighed 225g (3,500 grains); the full rounds weighed 460g and were 210mm long. The first shell was painted gray, and the second shell was painted yellow. The explosive shell was equipped with an impact fuse. There was also a training 24mm U-G shell, which weighed 225g and had a delayed fuse and a smaller load of explosives. The training shell was painted black. The velocity was 2,900 fps, and the shell could penetrate 30mm of armor plate at 200m and a 30-degree impact angle.