Tag Archive for 'swiss'

20 mm M.G. F.F.M. (Oerlikon): Aircraft Machine Gun

20 mm M.G. F.F.M. (Oerlikon): Aircraft Machine Gun

This flexible 20 mm aircraft machine gun, Oerlikon M.G. F.F., is the German Air Force version of the Swiss Oerlikon 20 mm machine gun.

The weapon is a blowback, inertia-operated, air-cooled machine gun for fixed or flexible mounts. It fires from an open bolt and has an electrically operated trigger mechanism. The cartridge-counting mechanism is also electrically operated. It has a pneumatic charging mechanism to retract the bolt for the first shot.

Some minor modifications of the Swiss version of this machine gun have been introduced. It is chambered to fit the short German 20 mm round, and the travel of the recoiling parts has been redesigned to conform. The barrel has been shortened and the gun lightened considerably. It has been in use in this form without material alteration since the beginning of the war.

The gun was originally intended as a fixed weapon and was termed the M.G. F.F. A later type, the F.F.M., is mechanically the same but in some cases is provided with a cooling cowling and a hand firing device for use as a free gun. It is used both as a flexible and a fixed gun.


Caliber         20 mm
Weight 76 1/2 lb.
Length 57 ins.
Feed Drum—60 rd. capacity
Length of barrel 32 1/4 ins.
Cooling Air
Operation Blowback (inertia) with solenoid trigger
Fire Automatic only
Rate of fire 450 to 500 rds./min.—cyclic

German: p. 251

2 cm s PzB (Solothurn s/8-1100): A.T. Gun (Ex-Swiss)

2 cm s PzB (Solothurn s/8-1100): A.T. Gun  (Ex-Swiss)

This gun, an improved version of the Solothurn 1933 model manufactured in Switzerland by the Waffenfabrik, is a magazine fed, recoil operated, semi-automatic shoulder weapon which can be fired from a bipod or a low-lying, pneumatic-wheeled carriage. The combined weight of gun and mount is approximately 200 pounds; the gun itself weighs 103 pounds.

The barrel is easily changed by giving it a half turn, thereby disengaging two lugs. Two types of magazines are used; one holding five rounds and the other ten.

The bolt is forward and all parts rigid when the firing pin strikes the cap of the projectile. When the last shot in the magazine is fired, the cartridge case is automatically ejected; then when a new magazine is inserted, the bolt is again thrown forward automatically and the gun is ready to fire.

Construction of all parts is exceptionally rugged and simple. The gun, which fires semi-automatically, is extremely accurate and easily handled. In comparison with the earlier model, the new gun shows a slight decrease in weight, increased muzzle velocity, and high armor-penetrating qualities. It also possesses the advantage of a dust-proof breech mechanism.


Caliber         20 mm (.79 in.)
Weight of gun (complete) 103 lb.
Weight of barrel with muzzle brake (approx.) 44 lb.
Length of gun (overall) 7.1 ft.
Length of barrel 4.25 ft.
Rifling 8 lands and grooves; 5° uniform twist
Muzzle velocity (reported) 937-991 yds./sec.

German: p. 134