Tag Archive for 'gun'

2 cm Flak 38: A.A./A.T. Gun

2 cm Flak 38: A.A./A.T. Gun

The Flak 38 was introduced in 1940 to replace the 2 cm Flak 30. Its performance does not differ materially from that of the earlier weapon, except for a higher cyclic rate of fire of 450 rounds per minute.

The gun is operated by short barrel recoil and the residual pressure of gas in the barrel. Recoil unlocks the breech and imparts rearward acceleration to the breechblock carrier. This rearward acceleration is assisted by gas pressure after unlocking has been completed so that the breechblock travels back with sufficient force to perform the operations of extraction, ejection, and compression of the return spring.

The energy required for closing the breech and carrying a fresh round to the chamber is provided by the return spring, assisted at first by the buffer spring.

The breechblock is of the Solothurn type. Any tendency toward rebound is counteracted by the impact of an inertia block at the end of the forward movement. The barrel has resistance rings which brake the recoil and forward movements of the barrel; a buffer and buffer spring arrest the backward movement of the breech block.

This weapon may be adjusted for either semi-automatic or full-automatic fire. It is fired by a foot pedal. Cartridges are fed from a 20-round curved box magazine hinged on the left of the gun.

The mounting consists principally of the base, cradle, traversing and elevating gears, firing mechanism, and lighting equipment.

Traverse is 10° per turn of handwheel in fine gear and 30° in coarse gear; rate of elevation or depression is 4° per turn in fine gear and 12° in coarse gear.

The weapon, which is transported on a trailer, may be mounted on railways cars or road vehicles. When traveling over difficult country, gun and mounting may be split into six loads.


Caliber         20 mm (.79 in.)
Length of tube
Weight (travelling position) 1,630 lb.
Weight (firing position) 924 lb.
Length (travelling position) 157 ins.
Height (travelling position) 67 ins.
Height (firing position) 30 ins. mounted flush
Width (overall) 71 ins.
Width of trail spread
Length of bore 44 ins.
No. of grooves
Width of grooves
Depth of grooves
Width of lands
Muzzle velocity (HE shell) 2,950 f.s. (A.P. shell)
2,624 f.s.
Max. range (horizontal) 5,246 yds.
Max. range (vertical) 4,012 yds.
Rate of fire 220 rds. (practical), 450 (theoretical)
Traverse 360°
Elevation +90°
Depression -20°
Length of recoil
Ammunition H.E. four types; A.P. two types
Wt. of 1 magazine of 20 rds 21 lb.

German: p. 136

2 cm Flak 30: Antiaircraft Gun

2 cm Flak 30: Antiaircraft Gun

The Flak 30 was the principal armament of German light antiaircraft units since the beginning of the war in Europe until the introduction of the 2 cm Flak 38 and 2 cm Flak 38 Vierling. The gun, which may be mounted on road or railway vehicles, is normally transported on a single-axle trailer which is drawn by either horse or motor vehicle. It is usually fired with its mounting on the ground and with the trailer removed. However, it can be fired from the trailer at both ground or aerial targets in emergencies.

This recoil-operated weapon is fed by a flat 20-round box magazine. The trigger mechanism is pedal-actuated; operation is either full-automatic or semi-automatic.

The barrel slides in the body with the barrel extension. A combined muzzle brake and flash eliminator is screwed to the muzzle and retained by a catch. The barrel extension is slotted on the right and left sides for ejection and feed respectively.

The body is formed to receive the barrel extension, which is hinged near the rear end of the body. The barrel return spring, buffer spring, buffer, and rod and sleeve are housed in a casing secured to the body at the rear.

The sights used are the Flakvisier 35, and the Linealvisier 21, the former is of the reflecting-mirror type with a data-calculating mechanism; the latter is a direct antiaircraft sight embodying course, speed, and range adjustment.

The gun carriage consists of a firm under carriage and a revolving top carriage supported on ball bearings. The under carriage is leveled by three adjustable feet, and is provided with a spirit level. The top carriage has a cradle which is adjustable for elevation. The elevation handwheel is located on the right side of the top carriage, and the traversing handwheel at the back.


Caliber         2 cm (.79 in.)
Length of tube
Weigth (travelling position) 1,697 lb.
Weight (firing position) 992 lb.
Length (travelling position) 160 ins.
Length (firing position)
Height (travelling position) 63 ins.
Height (firing position) 29 ins. mounted flush
Width (overall); (travelling position) 72 ins.
Width of trail spread
Length of bore
No. of grooves
Width of grooves
Depth of grooves
Width of lands
Muzzle velocity (H.E. shell) 2,950 f.s.
(A.P. shell) 2,624 f.s.
Max. range (horizontal) 5,246 yds.
Max. range (vertical) 4,012 yds.
Rate of fire 120 practical; theoretical 280
Traverse 360°
Elevation +90°
Depression -10°
Length of recoil
Ammunition H.E. (four types); A.P. (two types)
Wt. of 1 magazine of 20 rds 21 lb.

German: p. 135

30 mm Mk. 101 (Rheinmetall): Aircraft Machine Gun

30 mm Mk. 101 (Rheinmetall): Aircraft Machine Gun

The Mk. 101, also known as the M.G. 101, is a scaled-up version of the Solothurn S-18-1000, 20 mm antitank rifle used by the Swiss, Italians, Hungarians, and to some small extent the Germans. It is Germany’s first attempt to put a gun of over 20 mm caliber in an airplane. It was designed to be used principally for antitank work, but a high-explosive round is furnished for antipersonnel use.

It has been used mostly on the Russian front in the Heinkel 129, a heavily armored plane especially designed for ground attack. Neither the Mk. 101 nor the plane has worked out too well, and a new 23 mm Mauser cannon and two new 30 mm guns, the Mk. 107 and Mk. 108, are now coming into use in the German Air Force.

In the Heinkel 129, the Mk. 101 was fixed to a mount that could be attached to the bomb racks under the fuselage when the plane was sent on a tank-hunting or other special mission. The gun is a recoil-operated, magazine- or drum-fed, semi- or full-automatic, air-cooled weapon. It does not have a particularly high velocity; the armor-piercing, high-explosive tracer ammunition gives a velocity of 2,330 f/s, and the light armor-piercing tungsten carbide-cored round, 2,800 f/s.


Caliber         30 mm (1.18 ins.)
Operation Recoil
Feed system 10- or 20-round box magazine; 30-round drum
Weight 394 lb. (without mount)
Length 96 ins. (overall)

German: p. 253

20 mm M.G. 151/20 (Mauser): Aircraft Machine Gun

20 mm M.G. 151/20 (Mauser): Aircraft Machine Gun
The M.G. 151/20 mm and M.G. 151/15 mm (Mauser) were designed and built by the famous Mauser factory. The M.G. 151/20 is a fixed aircraft cannon, recoil-operated and belt-fed, using a disintegrating metallic link belt. It was manufactured also in a 15 mm form. Although the receiver group and the recoiling portions are not identical, the superficial appearance of the two guns is very similar.

Two of these guns are mounted in each of the Focke-Wulf FW 190 types of planes. In this installation, they are synchronized, firing through the propeller arc. They are installed in the wing roots about 12 inches out from the engine cowling with the barrels protruding about 2 feet beyond the leading edge.

This gun is electrically cocked and fired, and electric detonation of the cartridge has been adopted in order to facilitate interruption when it is used as a synchronized gun. A longer-barreled version with mechanical detonation is used when the gun is mounted to fire through the propeller hub as in the ME-109.

In the version mounted in the fuselage, the feeding device has a capacity of 50 rounds, but more rounds are usually carried for each gun when it is wing mounted. A streamlined container holds the gun and the belted ammunition in newer installations.

The following types of ammunition are used in the 20 mm version: H.E. with S.D. fuze; H.E.I./T. with S.D. fuze; A.P.I., A.P.H.E., and two different H.E.I. (S.D. fuze) rounds.


Caliber         20 mm (.787 in.)
Weight including electric control 93 1/2 lb.
Weight of barrel 22 lb., 14 oz.
Overall length 69 1/2 ins.
Length of barrel 43 1/2 ins.
Principle of operation Short recoil, no muzzle recoil booster, rotating bolt head
Cooling system Air
Feeding device Disintegrating metallic link belt
Capacity of belt 50 rds. and multiples thereof
Muzzle velocity (H.E.) 2,656 f/s
Rate of fire 780 r.p.m.
Ammunition used H.E. with S.D. fuze; H.E.I./T. with S.D. fuze; A.P.I.; A.P.H.E.; and two different H.E.I. (S.D. fuze) rounds.

German: p. 252

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

13 mm M.G. 131: Fixed or Flexible Aircraft Machine Gun

13 mm M.G. 131: Fixed or Flexible Aircraft Machine Gun

The German flexible aircraft machine gun, M.G. 131, 13 mm, is the Nazi tactical counterpart of the U.S. Browning, cal. .50, M2. Action is a Solothurn type—that is, the locking cam on a rotating bolt head engages a cylindrical locking collar to lock the action for firing. It is fed by a metallic disintegrating-link belt.

The M.G. 131 is used singly and in twin-mounted versions in hand-operated mounts and power-operated turrets in many German bombers. The recoil operation is assisted by a muzzle recoil booster. It is unusual in that the cartridges are ignited electrically instead of by a mechanically operated firing pin.

It is a recoil-operated, gas-assisted, belt-fed, air-cooled, automatic weapon that is coming into more extensive use in the German Air Force.


Caliber         13 mm (.512 in.)
Weight 40 lb.
Length 46 ins.
Rate of fire 900 rds./min.—cyclic
Muzzle velocity 2,370 f/s
Sights Refractor type on mount
Ammunition 13 mm Solothurn types—A. P., T; H. E., T

German: p. 222

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

2 cm Flak (Madsen): A.A./A.T. Gun (Ex-Danish)

2 cm Flak (Madsen): A.A./A.T. Gun (Ex-Danish)

The Madsen 20 mm automatic antiaircraft and antitank gun, a Danish weapon used largely by the German Navy, is also in service in the Bulgarian, Finnish, Hungarian, Portuguese, and Spanish armies. This rapid-fire model is a heavy-caliber, air-cooled, recoil-operated cannon, which is much more sturdy than the ordinary Madsen.

The fixed parts of the gun comprise the barrel casing with the sights, the frame with the magazine receiver, and the trigger plate with the trigger device. Recoiling parts comprise the barrel, the breech, and the breechblock. The connection between the fixed parts and the recoiling parts is established by means of the recoil arm and the link of the breech, together with the return mechanism.

The muzzle of the barrel is threaded externally to take the muzzle brake, and at the chamber to fit into the breech. It is secured to the breech by a locking pin. The oblong breech has an elongated opening in its left wall to accommodate the 60-round drum magazine feeding device.

The trigger mechanism can be set for either single-shot or automatic firing by means of a change over swivel.

The sighting gear, placed on the upper side of the barrel casing, consists of a leaf rear sight graduated from 100 to 1,800 m, and can be set in accordance with the graduations by means of the rear sight slide.

The cannon employs a universal mount.


Caliber         20 mm (.79 in.)
Weight in action 390 lb.
Weight of cannon 119 lb.
Length of cannon (overall) 7.38 ft.
Length of barrel 3.94 ft.
Rifling 10 lands and grooves; 5° twist
Rate of fire (practical) 200 rds./min.
Muzzle velocity 2,950 f/s
Range 6,015 yds.
Effective ceiling 6,960 ft.
Elevation 85°
Depression -5°
Traverse 360°
Ammunition H.E.; A.P.

German: p. 132

7.5/5.5 cm Pak 41: Tapered Bore Antitank Gun

7.5/5.5 cm Pak 41: Tapered Bore Antitank Gun

The 7.5 cm Pak 41, Germany’s latest antitank gun to be brought into service, is designed on the Gerlich or tapered-bore principle. The bore tapers from 7.5 cm at the breech to 5.5 cm at the muzzle, but the taper is not constant. The first part of the bore is cylindrical and rifled; the second, conical and unrifled; and the third, measuring 27.6 inches in length, is cylindrical and unrifled. There is also a muzzle brake. The life of the barrel is estimated at approximately 500-600 rounds. The weapon is long, low, and sturdy in appearance and has a semi-automatic breech mechanism of the vertical wedge type.

The carriage has a split trail and is mounted on metal wheels with solid rubber tires. As traction is by motor tractor, the carriage is fitted with pneumatic brakes controlled by the driver of the tractor. Torsion bar suspension is automatically cut out when the trails are opened.

An elevating mechanism of the sector type is on the right-hand side of the cradle, and a traversing mechanism of the screw type on the left. There is no equilibrator mechanism. The recoil mechanism contains a hydraulic cylinder and spring-type recuperator.

The sighting system, which is graduated up to 1,500 meters (1,635 yards), has four scales for use according to the actual muzzle velocity of the gun. Muzzle velocity drops considerably because of wear.


Caliber           7.5/5.5 cm
Weight in action         1.4 tons
Length of barrel (approx.)         170 ins.
Muzzle velocity (estimated)         4,123 f/s
Elevation         -10° to 18°
Traverse         60°
Armor penetration—A.P.C.

       Range in yards          Thickness of armor in inches 
                   Normal               30°    
       500  6.67  5.75  
       1,000  5.94  5.12  
       1,500  5.28  4.49  
2,000  4.63  3.94  

German: p. 123

Pz. Jäg. III/IV (“Nashorn”) für 8.8 cm Pak 43/1 (Sf) (Sd. Kfz. 164): S.P. Antitank Gun—”Rhinoceros” (formerly “Hornet”)

Pz. Jäg. III/IV ("Nashorn") für 8.8 cm Pak 43/1 (Sf) (Sd. Kfz. 164): S.P. Antitank Gun—"Rhinoceros" (formerly "Hornet")

The German 8.8 cm gun was designed in 1934 as the standard semimobile antiaircraft gun. Encouraged by success in Spain against armored vehicles the Germans went ahead with the production of A.P. ammunition for the weapon and the design of a more mobile carriage. Both were ready in time for the Battle of France. The 8.8 cm gun was a success in this battle, when it proved capable of dealing with the heavier French tanks, against which the standard German 3.7 cm A.T. gun was comparatively ineffective. The Germans next provided the gun with a new mounting from which the gun could engage tanks without being taken off its wheels. Finally a self-propelled mounting was introduced from which the gun can be fired against ground targets but cannot be used in its original A.A. role. Such an equipment is the tank destroyer “Hornet,” which consists of the 8.8 cm Pak 43/1 mounted on the chassis of a modified Pz. Kpfw. IV tank, the engine of which has been moved forward to a central position to provide a clear space for the fighting compartment at the rear. The “Hornet” mounts in effect the same gun as the “Ferdinand” but it is much more lightly armored and relatively much faster. Comparative figures for weight and maximum road speed of “Hornet” and “Ferdinand” are: 28 tons and 22 m.p.h., 80 tons and 12 1/2 m.p.h., respectively.

The 8.8 cm gun, fitted with muzzle brake, is mounted over the engine within a high, open-topped superstructure of thin armor plate and extends well over the front of the chassis. Its length, with muzzle brake, is 21 feet, 6 inches and its muzzle velocity with H.E. shell is 3,280 f.s.; with A.P.C.B.C. shell, 3,214 f.s. It will defeat 5 1/2 inches of homogeneous armor at 1,000 yards range and 30° angle of attack. Its maximum horizontal range is 16,200 yards and its rate of fire 15 to 20 rounds per minute.


Weight         25 tons
Length (excl. gun) 19 ft., 4 ins.
Width 9 ft., 7 ins.
Ground clearance 15 ins.
Tread centers 7 ft., 11 ins.
Ground contact 11 ft., 6 ins.
Width of track 15 ins.
Pitch of track 4 3/4 ins.
Track links 98
Fording depth 3 ft.
Theoretical radius of action:
     Roads (est.) 100 miles
     Cross-country (est.) 65 miles
     Road 22 m.p.h.
     Cross-country 12 m.p.h.
     Front plate 50 mm
     Sides 30 mm
Armament 8.8 cm Pak 43/1
Engine Maybach HL 120 TRM, 320 hp.
Transmission Synchromesh—6 speeds forward, 1 reverse
Steering Epicyclic, clutch brake
Crew 5

German: p. 34