Tag Archive for 'machine gun'

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

7.92 mm M.G. 37 (t) (Brno): Heavy Machine Gun (Ex-Czech)

7.92 mm M.G. 37 (t) (Brno): Heavy Machine Gun (Ex-Czech)

The M.G. 37 (t), 7.92 mm machine gun is one of the weapons taken over by the Germans after the occupation of Czech territory. It is gas-operated, belt-fed, air-cooled, and has a flexible mount.

The M.G. 37 has been designed for use on tanks and other Armored Force vehicles, but it is also effective as a heavy ground machine gun when mounted on a tripod.

The firing-control mechanism used in this weapon is different from that in other tank-mounted guns. Adjustments can be made for rapid and slow fire by use of a pivoting buffer system, and full-automatic or semi-automatic fire by use of an indicator on the trigger casing. A buffer is used to reduce the shock of the recoiling parts, and to insure smoother action. Initial cocking is accomplished by moving the cocking slide forward, the sear in this gun being moved to the front. By moving forward instead of to the rear, the type of cocking in this weapon makes it more adaptable for use in confined spaces such as tanks or other vehicles.

The weapon, being of Czech origin, uses an action similar to that of such guns as the Czech ZB, the Bren, and the British Besa. It is possible to change the barrel very easily on this weapon, although it is not a quick-change barrel. The gun does not have to be dismounted when this change is made.


Caliber         7.92 mm (.312 in.)
Weight 45 lb., 10 oz.
Length 43 1/2 ins.
Weight of barrel 14 lb., 14 oz.
Length of barrel 28 7/8 ins.
Operation Gas-operated
Feed Belt-fed
Rate of fire         520 rds./min.—slow
820 rds./min.—fast

German: p. 216

7.92 mm M.G. 42: Dual-Purpose Machine Gun

7.92 mm M.G. 42: Dual-Purpose Machine Gun

This is the latest known type of German machine gun. It is apparently intended eventually to replace the M.G. 34 which it resembles somewhat. The M.G. 42, however, is far easier to manufacture than the earlier gun and is less finished in appearance, because of the wide use of stamping, welding, and riveting.

The M.G. 42 is air-cooled, recoil-operated, gas-assisted, belt-fed, and is fitted with a quick barrel-changing device. It has a much higher rate of fire than the M.G. 34, but it is said to be less accurate than the earlier weapon.

This gun can be used on a bipod as a light machine gun, on a tripod as a heavy machine gun, as an antiaircraft machine gun, and for numerous other special purposes on special mounts. The barrel jacket and receiver are constructed of pressed steel welded lengthwise with runways welded into the receiver for the bolt. The cover and feed mechanism, which is made of stamped steel, is hinged at the front of the receiver. The shoulder stock is plastic. The right side of the barrel jacket is left open so that when the bolt is retracted the barrel may be removed and changed. A lever in a recess on the right side of the barrel jacket forces out the rear of the barrel. This is a very simple and fast barrel change.

The action is different from the M.G. 34 in that the bolt does not lock to the barrel extension by a turning bolt head, but rather by two rolls set in the bolt head which lock bolt and barrel extension together by running into camways in the barrel extension when the bolt head hits the barrel extension.


Caliber         7.92 mm (.312 in.)
Weight of gun with bipod 26 lb.
Weight with heavy machine gun tripod mounting 65 1/2 lb.
Overall length 48 ins.
Principle of operation Recoil, assisted by muzzle recoil booster
Cooling system Air
Feeding device Metallic non-disintegrating link belt
Capacity of feeding device 50 rd. lengths and multiples thereof, and 50 rd belt drums
Sights (a) Inverted V front sight and leaf rear sight with open V notch graduated from 200 to 2,000 meters.
  (b) Separate antiaircraft rear sight hinged on the rear sight base.
  (c) Antiaircraft ring-sight to be fitted on barrel jacket.
  (d) Telescopic sight on a tripod when used as a heavy machine gun.
Rifling 4 grooves right-hand concentric
Muzzle velocity 2,500-3,000 f/s
Maximum range (as L.M.G.) 2,200 yds.
Effective range (as L.M.G.) 600 yds.
Rate of fire (cyclic) 1,335 r.p.m.
Ammunition used All 7.92 mm Mauser ground types (except antitank rifle ammunition)

German: p. 215

7.92 mm M.G. 81: Flexible Aircraft Machine Gun

7.92 mm M.G. 81: Flexible Aircraft Machine Gun - Luftwaffe WW2

The German Aircraft Machine Gun, M.G. 81, 7.92 mm, is a Mauser designed air-cooled, belt-fed, recoil-operated (gas assisted) weapon which fires from an open bolt. The weapon is light and easily manufactured and is now used in place of the German M.G. 15 in many German aircraft. It is a flexibly mounted gun and serves as an observer’s weapon.

A “Solothurn type” bolt head is rotated by cams and locked to the barrel by an interrupted thread. It appears to be a speeded-up type of the light machine gun, M.G. 34. The higher rate of fire is achieved by a powerful buffer spring fitted into the body, as well as by general lengthening of all parts, and some redesign. The recoil operation is assisted by a nuzzle booster. The barrel is unusually short, being only 183 inches long. A push-type safety catch is located in the trigger guard just forward of the trigger. This can be moved only when the gun is cocked.

The weapon is fired only at full-automatic fire. The method of feeding is by a disintegrating-link belt through the feed block. A barrel casing made of perforated sheet metal encloses the barrel and fits into a sleeve which screws into the front of the body. The weapon has a muzzle booster which screws onto the barrel housing. This weapon is made and used in a dual mount with single trigger operation for both mounts.


Caliber        7.92 mm. (.312 in.)
Weight 13 lb., 14 oz.
Length 35 ins.
Length of barrel 18.75 ins.
Operation Recoil, gas assisted
Fire Automatic only
Muzzle velocity* 2,500-3,000 f/s
Rate of fire 1,200 to 1.500 rds./min.
Ammunition All 7.92 mm Mauser types

*Muzzle velocity varies according to ammunition used.

German: p. 221

7.92 mm M.G. 17: Fixed Aircraft Machine Gun

7.92 mm M.G. 17: German WW2 Fixed Aircraft Machine Gun

The German 7.92 mm aircraft machine gun, M.G. 17, is an air-cooled, recoil-operated, gas-assisted, belt-fed, pneumatically charged, fixed weapon fired electrically by solenoid. It differs from the M.G. 15 in that it fires from a closed bolt. Three types of links have been found used with the belt feed of this weapon: sectionally disintegrating, fully disintegrating, and nondisintegrating. The gun, which has a fixed mount, is well constructed with excellent machining throughout.

All parts are of steel with the exception of the rear buffer housing which is of cast dural with an anodized finish. The rest of the gun is covered with a good parkerized finish. The barrel is connected to the barrel extension by an interrupted thread type fastening. The bolt is of the Solothurn rotating type and operates on small steel rollers.

The M.G. 17 is used in many types of German aircraft, and is stationed in various positions so that it may be fired unsynchronized or synchronized through the propellor arc by solenoid.


Caliber         7.92 mm (.312 in.)
Weight 27 lb., 11 oz.
Length 47 3/4 ins.
Length of barrel 23 5/8 ins.
Muzzle velocity 2,800 f/s
Rate of fire 1,000 rds./min. (synchronized)
1,100 rds./min. (unsynchronized)
Operation Recoil, gas assisted
Fire Automatic only
Rifling 37° uniform right-hand twist, 1 turn in 10 ins.

German: p. 220

7.92 mm M.G. 34/41: Dual-Purpose Machine Gun

7.92 mm M.G. 34/41: Dual-Purpose Machine Gun

The German 7.92 mm machine gun, M.G. 34/41, represents one of the later developments of the M.G. 34. These developments occurred in the following order: the M.G. 34; M.G. 34 modified; M.G. 34s; M.G. 34/41. In the course of development, the original pattern of the weapon has been largely retained, but each stage has tended toward simplification and elimination of machined parts.

The M.G. 42 is a new design but has the same tactical employment. It is distinguished by a high cyclic rate of fire and fewer machined parts. The M.G. 42 is described on a separate page.

The M.G. 34 modified is used principally in armored vehicles and differs from the M.G. 34 in that it has a heavier barrel jacket adapted to fit ball-type tank hull mounts, a simplified firing-pin nut lock, and bipod clamps for attaching bipod in emergency use; it has no A.A. sight bracket. It can also be mounted on antiaircraft and heavy ground mounts.

The M.G. 34s and the M.G. 34/41 are identical in appearance, except for the barrel jackets, but are marked as distinct models. They differ from the M.G. 34 as follows: provision for full-automatic fire only; simplified trigger group; shorter barrel with enlarged muzzle end; elimination of firing-pin lock nut; large buffer group; heavier recoil spring; modified feed mechanism. These models can be used on antiaircraft mounts but appear designed for the heavy ground mount.


Caliber        7.92 mm (.312 in.)
Weight 24 1/2 lb. w/o bipod
Weight of barrel 3 3/4 lb.
Length 44 1/4 ins.
Length of barrel 19 3/4 ins.
Muzzle velocity* 2,500-3,000 f/s
Rate of fire 800-900 rds./min. cyclic
Operation Recoil, gas assisted
Ammunition All 7.92 mm Mauser ground types

*Muzzle velocity varies according to ammunition used.

German: p. 214

7.92 mm M.G. 34: Dual-Purpose Machine Gun

7.92 mm M.G. 34: Dual-Purpose Machine Gun

The M.G. 34 is a standard machine gun of the German Army. It cannot be compared directly with any American automatic weapon. It is a multi-purpose weapon and is used as a light machine gun, a heavy machine gun, an antiaircraft machine gun, and also on tanks and other vehicles. Because of its adaptability, it is the most common automatic weapon used by the German Armed Forces.

Without bipod mount, the M.G. 34 weighs 24 1/4 lb., and is occasionally fired by the use of a second soldier’s shoulder as a rest. A light bipod adapts it for prone fire and with tripod mount this becomes a heavy machine gun.

The M.G. 34 is a recoil-operated, gas-assisted weapon, belt-fed, and air-cooled. It operates on the Solothurn rotating bolt-head principle. A simple mechanism makes it easy to exchange a heated barrel for a cool one. It is designed to deliver semi-automatic or full-automatic fire.

Studies at Aberdeen Proving Ground show that it is very easy to disassemble in the field, but cannot be regarded as an easy gun to manufacture on a mass production basis, as compared with the M.G. 42.

Studies of captured guns show that this weapon has a high rate of fire—too high for a light machine gun—resulting in poor accuracy in full-automatic operation. When used as a heavy machine gun it shows excellent stability. It is extremely critical as to adjustment, lubrication, and foreign matter.


Caliber       7.92 mm (.312 in.)
Weight of gun with bipod26 1/4 lb.
Weight with H.M.G. Tripod mounting68 1/2 lb.
Overall length48 ins.
Principle of operationRecoil, assisted by muzzle booster. Solothurn type action.
Cooling systemAir
Cartridge feedFlexible metallic link belt containing 50 rds. and multiples thereof. Also 50 rd. belt drums and 75 rd. saddle-type drums.
Sights(a) A blade front sight and vertical leaf rear sight with open V notch graduated from 200 to 2,000 meters.
(b) An aperture rear sight for use with a “cartwheel” type antiaircraft front sight.
(c) A telescopic sight is used on the heavy machine gun tripod mount.
Rifling4 grooves right-hand concentric
Muzzle velocity2,500 to 3,000 f/s depending on type of round used.
Maximum range5,000 yds.
     Effective—heavy3,827 yds.
     Effective—light600 yds.
Rate of fire (cyclic)800-900 r.p.m.
     (practical)100–120 r.p.m.

German: p. 213