Oerlikon 20mm

History

The moment of birth of the legendary Swiss 20mm Oerlikon automatic anti-aircraft gun was actually in the German Empire when it was first used in the First World War. The original form was the "20mm Becker", an automatic weapon with a 20x70mmRB projectile designed for use by the Luftwaffe. Despite this early initiative, the weapon was used in a variety of roles and is remembered as part of many battleships.

After the Armistice War ended in 1918, the manufacture of the weapon was transferred to neighboring Switzerland in 1919 due to restrictions imposed by the Treaty of Versailles, severely limiting Germany's war-fighting capabilities. The trademark responsible for this weapon is now SEebach Maschinenbau Aktien Gesellschaft (SEMAG).

Along with the Swedish 40mm Bofors, the Swiss Oerlikon 20mm gun was one of the most important artillery developments of the 20th century - it was used in land-based (fixed or towed), naval platforms and aircraft weapons. Finally, for naval characters, mounts are achieved with one, two or even four shots. This weapon proved to be an integral part of the classic warships of WWII - from small patrol boats to larger warships and aircraft carriers operating in conflict.

Automatic guns were used by all parties to the war, including Britain, France, the United States, Germany, Italy, and Japan.

The core of this weapon relies on a gas-driven recoil action (using Advanced Primer Ignition - API) to produce an autofire effect. The recoil spring wraps around the barrel and helps increase the required repeat accuracy.

Feeding was initially via a 20-round magazine or a 60-round drum magazine, although the latter was the more commonly accepted method. High Explosive (HE) rounds are standard projectiles with a range of up to 7,400 yards (absolute maximum), but the direct aim tapers off after about 1,600 yards.

SEMAG introduced a new model SEMAG L in 1924, which combined a faster rate of fire with a heavier frame and chambered for the 20 x 100 mm RB projectile. However, the addition of this product line was not successful.

The product was eventually adopted by Werkzeug Maschinenfabrik Oerlikon, headquartered in the north of Zurich, and the range of the genre only grew after that, when several world powers obtained local license production rights, and they adopted the local name.

The next big brand to emerge was the 1927 Oerlikon S model. This product retains the 20 x 110 mm RB rifling, but has increased muzzle velocity for better penetration, allowing it to be used in dual capabilities (air deployment and land targeting).

The Oerlikon 1S followed in 1930 and was classified as an improvement. The Oerlikon AF and Oerlikon AL models were introduced as dedicated aircraft weapons, designed to be mounted on a trainable stand, and a 30-round drum was introduced for this application.

Permanently mounted version first introduced in 1935, available as a faster-firing Oerlikon FF (at about 520 rounds per minute) and a variable ammunition drum ranging from 45 to 100 rounds. This model holds a 20x72mmRB projectile. The localized German version became the famous MG FF gun, but with a 20x80mm RB projectile. The FF in service with the Japanese Navy became the Type 99-1.

A similar Oerlikon FFL has a reduced rate of fire (to 500 rpm) but fires a heavier 20mm projectile. The Japanese navy's counterpart became the Type 99-2. The heaviest projectile fired is from the Oerlikon FFS model, which has a further reduced rate of fire (470 rpm).

The Oerlikon FFS developed in 1938 into the Navy's classic Oerlikon SS with a rate of fire of 650 rounds per minute. The SS model became the naval standard for World War II combat.

In 1942, the Oerlikon 1SS debuted, followed in 1945 by the Oerlikon 2SS model - both of which attempted to increase the rate of fire.

Surprisingly, the Oerlikon product is still in use today (2015), even though it was first shown in the First World War. This durability of military weapons demonstrates the design's outstanding interior functionality, battlefield versatility and tactical desirability.

The modernized form will only continue the line of producing "100-year-old guns" - a real rarity in military service.

Specification

Basic

Roles

Dimensions

Performance

Performance

Armor

Variable magazine and drum numbers, depending on application.

Changes