Tag Archive for 'cannon'

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.

SPECIFICATIONS

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.

SPECIFICATIONS

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.

SPECIFICATIONS

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.

SPECIFICATIONS

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.

SPECIFICATIONS

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

20 mm Aircraft Cannon Type 99 Mk. II

20 mm Aircraft Cannon Type 99 Mk. II

This is a gun of higher power than the Type 99 Mk. I, 20 mm cannon. Like the earlier gun, it operates on the Oerlikon principle and is found both with drum type magazine feed (Mod. III—top photo) and with belt feed (Mod. IV—lower photo).

The principal differences between this model and the Mk. I consist of a longer barrel and a longer chamber. The barrel protrudes 18 inches beyond the leading edge when mounted in the wings of fighter aircraft. The projectiles used are identical to the Mark I, but the cartridge employed contains approximately 40% more propellant than the older type, thereby increasing the velocity of the Mk. II 500 to 700 foot seconds. The muzzle velocity of the weapon varies from 2,500 to 2,700 foot seconds depending upon the type of projectile used. The gun has been found in ZEKEs and HAMPs. It is probably fitted in RUFEs and as a flexible gun in the tail turret of BETTY.

SPECIFICATIONS

Caliber         20 mm (.787 in.)
Weight of gun 67 lbs.
Length of gun (overall) 73 ins.
Length of barrel 47 ins.
Length of rifling 41.5 ins.
Number of grooves 9
Depth of grooves 0.026 in.
Twist of rifling Right hand
Principle of operation Blow back
Feeding device French drum or belt
Capacity of drum 100 rds.
Cooling system Air
Sights Reflector type
Charging mechanism Pneumatic
Firing system Flexible cable
Effective range (est.) 600-700 yds.
Rate of fire (est.) 400-500 r.p.m.
Ammunition Ball, A.P., A.P./I., T., H.E., H.E./T., H.E./I.

Japanese: p. 254 (August 1, 1945)

20 mm Aircraft Cannon Ho 5 (Browning Principle)

20 mm Aircraft Cannon Ho 5 (Browning Principle)

This weapon, an improvement on the 12.7 mm Japanese copy of the U.S. Cal. .50 aircraft machine gun, is a recoil-operated, disintegrating metallic link belt-fed, air-cooled, aircraft machine cannon. It is mounted as a fixed weapon and as such it is fired electrically by remote control.

The recoil mechanism consists of a metal cylinder into which is fitted a coil spring. Through the center of this extends a 5/16-inch rod which screws into a brass bushing. The rod extends through the spring follower which rests on the coil spring and is secured by two lock nuts. Buffering action takes place in the recoil direction only. There is no quick change barrel. Because of the weight of the bolt and the heavy recoil spring, a booster is used, this being found in the flash hider.

The gun has a high cyclic rate of fire, muzzle velocities of 2,304 f/s (A.P.), 2,430 f/s (H.E.), and a penetration performance of 7/8-inch homogenous plate at 20° at 200 yards; 1/2-inch at 20° at 580 yards. The maximum weight lifting capacity of the belt is 62 pounds.

The disassembly of the weapon is the same as the Browning Cal. .30 and Cal. .50 machine guns with a few minor exceptions. The Japanese weapon has no back plate latch. The back plate is held in place by two pins, one at the top, and one at the bottom.

SPECIFICATIONS

Caliber         20 mm (0.79 in.)
Weight w/accessories 104 11/16 lbs.
Weight w/o accessories 86 3/4 lbs.
Length (overall) 63 3/4 ins.
Sight radius
Principle of operation Recoil with muzzle cup
Feeding device Metal link belt type
Capacity of feeding device 100 rounds
Cooling system Air
Ammunition types A.P., H.E., Incendiary
Cyclic rate 950 r.p.m.
Type of sight Reflector
Weight of barrel 12 1/8 lbs.
Length of barrel 35.4 ins.
Length of rifling 31.5 ins.
Rifling
   Twist R.H.
   Form
   No. of grooves 8
   Depth of grooves
   Width of grooves
Chamber pressure
Muzzle velocity (A.P. Shot) 2,304 f/s
         (H.E. Shell) 2,430 f/s
Effective range 600 yds.

Japanese: p. 252 (June 1, 1945)

20 mm Aircraft Automatic Cannon, Model 99 Mk 1 Flexible

20 mm Aircraft Automatic Cannon, Model 99 Mk 1 Flexible

This weapon is an air-cooled, blowback-operated, Oerlikon type machine cannon. It operates on the same basic principle as all Oerlikon cannons of this type. The Japanese gun is a close copy of the Swiss gun, in that it is designed for full automatic fire only. The gun is manufactured in Japan on Swiss machinery. The above illustration shows the flexible version.

A significant feature is that the parts which are subjected to little wear, such as the grips, mounts, gunners’ shoulder rest, and other exterior parts are generally made of light weight metal.

This weapon is almost identical with other Model 99 (1939), 20 mm aircraft cannon reported to be used in the majority of Japanese planes, both as fixed guns in fighter craft, and as flexible guns in bombing planes. The weapon is fed from a drum type magazine. It is cocked or charged by manual means, and has no semiautomatic charger or rounds counter. The cocking handle is rotated to draw the recoiling parts to the rear and cock the gun for the first shot, the gun firing from an open bolt. Cocking operations for succeeding shots are performed by the blowback operation of the gun itself.

SPECIFICATIONS

Caliber         20 mm—0.87 ins.
Weight (without magazine) 62 lbs.
Weight of 60 rd. magaine (empty) 20 lbs.
Length (overall) 55 ins.
Length of barrel 30 ins.
No. of grooves 9; Uniform right hand twist
Width of grooves
Depth of grooves 0.022 in.
Width of lands
Muzzle velocity (shell) 1,930 f/s.
Cyclic rate 510 r.p.m.
Traverse Flexible aircraft
Length of recoil
Turns of cocking handle required to cock piece 11 1/2 ins.
Ammunition HE; HE with tracer; HE with self-destroying tracer; HE-I; AP; AP tracer; AP-HEI; Long burning tracer; Practice
Wt. of HE projectile 4.50 ozs.
Type of feed 60 rd. drum

Japanese: p. 251 (June 1, 1945)

7.62 cm Feldkanone 36 (r): Field Gun (Ex-Russian)

7.62 cm Feldkanone 36 (r): Field Gun (Ex-Russian)

The 7.62 cm F. K. 36 (r) is a gun of Russian design and manufacture. The Germans captured so many pieces during the early months of the invasion of Russia that they were adopted by the German Army both in the original form for standard divisional field guns and as antitank guns known as the 7.62 cm Pak 36 (r) described on page 116.

Both weapons have the same general characteristics: built-up tubes fitted in reinforcing jackets, vertical sliding breech blocks, hydropneumatic recoil mechanisms, and split trail carriages. In addition to a number of minor changes, the principal difference is in the much greater chamber length of the Pak 36 (r)—28.25 inches compared with 15.20 inches, and the addition of a muzzle brake to the Pak 36 (r).

The breech mechanism may be operated either by hand or semi-automatically. Extractors housed in the breech ring are operated by cams when the block opens. A hand control on the left side of the breech ring is provided in case the cartridge fails to eject. The firing mechanism is a continuous pull type.

SPECIFICATIONS

Caliber     76.2 mm (3 ins.)
Weight (complete)3,619 lb.
Weight (firing position)3,564 lb.
Length (overall)22 ft. 6 1/4 ins.
Length of gun153 ins.
Height (traveling position)
Height (firing position)
Width (overall)
Width of trail spread
Length of rifling120 ins.
Length of tube12 ft. 2 ins.
No. of grooves32 R.H. Polygroove form; Twist-1 in 25 Uniform
Width of grooves0.196 in. (5 mm)
Depth of grooves0.033 in. (0.84 mm)
Width of lands0.078 in. (2 mm)
Muzzle velocity (A.P.H.E. shell)2,249 f/s (H.E.—2,335 f/s)
Max. range (horizontal) (A.P.-H.E.)14,000 yds.
Rate of fire
Traverse60°
Elevation72°
Depression
Length of recoil (average)H.E.-A.P.H.E.—31.1 ins.
AmmunitionH.E.-A.P.H.E.-A.P. 40
Wt. of ProjectileH.E.—13.45 lbs.
 A.P.H.E.—14.2 lbs.
 A.P. 40—9.2 lbs.

German: p. 116.1

30 mm Mk. 108 A-3: Aircraft Machine Gun

30 mm Mk. 108 A-3: Aircraft Machine Gun

The Mk. 108 A-3 is an automatic, air cooled, belt-fed weapon operated by blowback and firing electrically from an open bolt. Initial cocking and initial depression of the sear to release the bolt are accomplished by compressed air. The gun is mounted on its side, and fires through the propeller hub in ME 109 G fighters. It is attached at the forward end of the receiver to a blast tube which extends through the engine. This gun is unusual in being a blowback operated, low muzzle velocity weapon.

Sixty rounds of ammunition are fed by means of a disintegrating belt from an ammunition can mounted above the gun. On release of the sear, the bolt travels forward under the action of two driving springs. A projection on top of the bolt passes through the ring extracting a round and forcing it into the chamber. After firing the empty cartridge case reseats itself in its link. The ejection is accomplished by pawls actuated by camming grooves cut in the top of the bolt. Position of a new round takes place by the same action. A feature of the gun is the fact that the barrel and receiver do not move in recoil, the entire force of which is taken up by the rearward motion of the bolt against driving springs which act as buffers on recoil. There is no locking action between the barrel and bolt at any time.

All ammunition found to date has been high explosive, high explosive-tracer, incendiary and incendiary tracer. It is doubtful if the muzzle velocity is high enough for the effective use of armor piercing ammunition.

SPECIFICATIONS

Caliber         29.6 mm (1.17 in.)
Weight (total) 265 lb.
Weight of gun 136 lb.
Weight of mount 28 lb.
Weight of ammunition can 36 lb.
Weight of ammunition (60 rounds) 65 lb.
Weight of recoiling parts 24 1/2 lb.
Length of gun with blast tube 7 ft. 6 3/4 ins.
Length of gun 3 ft. 5 1/4 ins.
Length of barrel 21 1/2 ins.
Number of lands and grooves 16
Maximum length of recoil of bolt 11 1/2 ins.
Rate of fire 500 rds./min.
Muzzle velocity (approx.) H.E.—1,650 f/s.*

*Not verified

German: p. 255