55 S 55

55 S 55 (also called Raikka) was a Finnish recoilless anti-tank weapon from the mid-1950s. The numbers refer to diameter of the launching tube in millimetres and year of entering to service. S stands for Finnish word "sinko" (recoilless weapon).

History
During the later stages of World War II, Finland received large shipments of German Panzerfausts (F1 and F2) and Panzerschrecks. These weapons were used after the war, but soon the need for modern replacement arose.

Dr. Ilmari Liikkanen, who worked for the company Raikka Oy, is usually considered to be the person behind the construction of the 55 S 55 (55 mm, RCL m/55). Not much is known about the development process, but it is believed that the Soviet RPG-2 was a big influence, since the principle is similar. However, the principle differs from the later RPG-7 because the shots of the 55 S 55 weren't rocket-propelled.

The 88 millimetre HEAT grenade is capable of penetrating 300 millimetres of RHA +- 40 millimetres. The longest recommendable distance for stationary targets is 200 metres and to moving targets 150 metres. A fragmentation grenade is also available. If capped the fragmentation grenade can penetrate obstacles such as light doors, bushes and windows before exploding. These can be shot up to 700 metres against stationary targets.A rifle calibre practice barrel 7,62 X 54 R could be installed inside the launching tube.

The aim is optical with stadiametric rangefinder reticule. There's provision for illuminating the reticule and the stadia marks.

The 55 S 55 was the standard anti-tank weapon of the Finnish Army from late 50s but has been phased out since 1980s giving way to M72 LAW and Apilas. The weapon was operated by a two man team, loader and the gunner.

The main disanvantage of the weapon was slow muzzle velocity causing an arched trajectory. This exposed the grenade to wind conditions and branches in covered terrain. Also the smoke and noise when firing could reveal the location making the user(s) a target. The weapon had a tendency to nod on launch requiring determined handling.