Luftwaffe Cannons and Machineguns topic.

[CharlesBronson]

Is worth to mention that this cannon was also used in a double turret in the He-177. Few were converted, one used as a transport to retrieve stalingrad, this aircraft also have the mission to shoot the russian flak emplacement "in the pass"

And was "re-introduced " in some Bf-110Es and employed against tanks in the African desert.

http://i12.tinypic.com/2pru4va.jpg


Rheinmetall Maschinen Kanone MK-103

The good results obtained with the MK-101 and his cartrigde caused that the development of a improved weapon.

The new cannon would be more dedicated to the air-to-air combat, because the heavy weight and slow firing of the MK-101 made very inadecuate for that task.

Once again Rheinmetall Borsig put their hand on work and in the late 1942 they had his new design complete.[/FONT]

The MK 103 used a new system of short recoil with a bolt assisted by a gas to unlock the chamber, a hole in the barrel deviated a small quantity of the combustion gases and move a piston back.

That incremented the speed of the bolt s movement and therefore the rate of fire.

The MK-103 weights 145 kg, had an overall lenght of 2320 mm and his rate of fire was betwenn 380-420 rpm.

There was also a MK 103M variant, that was to be installed in the big V-12 engines like the Jumo 213 and Daimler DB-603. Is worth to note that despite some wrong sources the MK 103 was NEVER put in service with the Me-109K...simply because there was no enough room inside this fighter to put in, for that it would be needed to move the cockpit backwards about 20 cm, and still the gun barrel shall potrude through the Messers nose.

 

[CharlesBronson]

Edited (repeated post)

 

[Tony Williams]

Rheinmetall Maschinen Kanone MK-103There was also a MK 103M variant, that was to be installed in the big V-12 engines like the Jumo 213 and Daimler DB-603. Is worth to note that despite some wrong sources the MK 103 was NEVER put in service with the Me-109K...simply because there was no enough room inside this fighter to put in, for that it would be needed to move the cockpit backwards about 20 cm, and still the gun barrel shall potrude through the Messers nose.

To clarify - the MK 103 could not be installed in any Bf 109, but the MK 103M could - it was specifically designed for that. According to Schliephake, one Bf 109K-10 was fitted with the MK 103M for test purposes, but the tests were not successful - I don't know why.

 

[CharlesBronson]

I think that the nose of the BF-109 was to short for this and it would require some major modifications, If was actually mounted in the K-10 probably several troubles in feeding and everything else.



MK-103 in attack airplanes:

One of the first user of the new cannon was the Hs-129 from the Sch 1 in the Western front, The HS-129 armed in that way arrived to theirs bases in Ukrania in april 1943. This aircrafts had a stunning performance in the big armoured clash of Kursk.

3 images of the luftwaffe groundcrew feeding the Mk-103.

a)- Introducing the belt, note the mix between the Steel AP and Pzg40.

b) Closing the receiver plate.

c) -In here the technical oficcer adjust the frontal support jack, this absorbed a big deal of vibration and thus increased the gun saccuracy.

MK 103 in Fw-190:

This gun was installed in two containers below the wings. Two types of containes were developed one for the FW-190A-5 and other for the Fw-190A-8 and F-8. In both cases the gun in this emplacement was feed by a metallic belts of 32 cartrigdes. It seems that the recoil forces and vibration were too much to the Focke Wulf ( despite the strong fabrication of the Wurger wings) and just few aircraft were armed in this way.

FW-190A-8/R3 .

Teorically the electric ignition in this weapon allow to shoot through the propellers, however test with an underbelly MK was a complete failure since the variation in rate of fire caused some "hang" shots, with the predictable consecuences.

 

[Tony Williams]

I think that the nose of the BF-109 was to short for this and it would require some major modifications, If was actually mounted in the K-10 probably several troubles in feeding and everything else.

Schliephake is the best source I know on the subject of Luftwaffe armament installations, so I trust his account.

The problem with fitting large guns in engine mountings was that there had to be enough space between the back of the engine and the pilot's seat to fit the gun breech and ammunition magazine. The gun barrel wasn't a problem - there was lots of length running from the back of the engine to the prop - as long as it was less than 70mm wide (the diameter of the tube running between the cylinder banks of the 109). The problem with the MK 103 was that there was a gas duct running alongside the barrel for part of its length, and this meant that the barrel couldn't fit in the tube. The MK 103M was redesigned to avoid the need for the gas duct, so the entire barrel could fit within the 70mm tube through the engine.

However, even with the MK103M it would undoubtedly be a very tight squeeze as you say.

 

[CharlesBronson]

I sought and sought but failed to found a picture of this K-10 variant, The only i ve foud is the K-14 with 3 MK-108 guns.

 

[CharlesBronson]

MK 103 in fighters:

A Ju-88C night fighter with two MK 103 in a underbelly pod, note the angled barrels.

The 30 mm high velocity gun also was used in some special Me-262 like the Me-262A-1a/U1, it carry a heavy batterie, 2 x MK 108 plus 2 x Mg-151/20 and two more Mk 103 with 70 rounds per gun potruding through the nose. Just 4 or 5 A-1a/U1 were actually deployed, one was used by Heinz Bär.

The Ta-152C was one of the few single engine piston aircraft who could handle the MK 103 between the Jumo 213 V.

The Dornier Do-335 was another, in the B-2 variant also were one Mk-103 embeded in each wing.

 

[net_sailor]

The 30 mm high velocity gun also was used in some special Me-262 like the Me-262A-1a/U1, it carry a heavy batterie, 2 x MK 108 plus 2 x Mg-151/20 and two more Mk 103 with 70 rounds per gun potruding through the nose. Just 4 or 5 A-1a/U1 were actually deployed, one was used by Heinz Bär.

Probably only three A-1a/U1 were produced.
Heinz Bar used six barell Schwalbe, but this exemplar was equiped with MK 108 (Me 262A-1a/U5 W.Nr. 111355).

The Ta-152C was one of the few single engine piston aircraft who could handle the MK 103 between the Jumo 213 V.

The Ta 152C-3 was fitted with MK 103 (C-0 and C-1 used MK 108 cannon). Tanks in C variant were powered by DB 603L or LA enginies.

The Dornier Do-335 was another, in the B-2 variant also were one Mk-103 embeded in each wing.

Every Pfeil variant had a single MK 103 cannon firing trough propeler hub also.

 

[Tony Williams]

Probably only three A-1a/U1 were produced.

I've never understood the rationale behind that installation: the MK 103, MK 108 and MG 151/20 all had significantly different ballistics.

It would have made a lot more sense IMO to combine the MK 103 with the 15mm MG 151, as the ballistics were comparable.

The Ta 152C-3 was fitted with MK 103 (C-0 and C-1 used MK 108 cannon). Tanks in C variant were powered by DB 603L or LA enginies.

Every Pfeil variant had a single MK 103 cannon firing trough propeler hub also.

I'm not clear whether these installations used the MK 103 or the MK 103M.

 

[net_sailor]

I've never understood the rationale behind that installation: the MK 103, MK 108 and MG 151/20 all had significantly different ballistics.

It would have made a lot more sense IMO to combine the MK 103 with the 15mm MG 151, as the ballistics were comparable.

Exactly! This set was introduced on Do 335. Ta 152C-3 had simmilar mix of MG 151/20 and MK 103

I'm not clear whether these installations used the MK 103 or the MK 103M.

Good question! There is one Pfeil preserved in NASM. I'm wonder is she still armed and dangerous

 

[CharlesBronson]

Some examples of ammunition of 30x184B, the cartrigdes used by the MK-101 had percussion primer, the ones used by the Mk-103 had electric primer.


Panzergranate 40 L-spur :

The favorit against soviet tanks, It had a 16 mm diameter and 231 grams tugten carbide core and base tracer. Muzzle velocity 960 m/s. Penetration about 80 mm of homogeneous armor at 100 meters. Projectile weight 330 grams.



Panzerbrandgranate Elektron:

Armor piercing incendiary, Steel shot filled with elektron , 410 grams, muzzle speed about 700-710 m/s. Penetration 32 mm armor at 150 meters.



3 cm Minengranate L-spur O. Zerl.

High explosive mine type, 330 grams, with day tracer but without self destruction device. Muzzle speed 900 m/s.



Panzersprenggbrandgranate L-spur M. Zerleger.

The devoted antitank aircrafts like the Hs-129 could use also this variant, an armor piercing, explosive incendiary amunition, with day tracer and self destruction...All in one ¡¡¡

The steel core bullet have a ballistic cap and filling of explosive nitropenta and incendiary Elektron. Weight 450 grams, muzzle speed 700 m/s.

 

[CharlesBronson]

Rheinmetal Borsig MK 108:

In many ways, the Rheinmetall-Borsig MK 108 30mm cannon was considered to be a masterpiece of weapons engineering, due to it's compact size, ease of manufacture and hitting power. Although it was first designed by Rheinmetall-Borsig in 1940 as a private venture, the design was finalized in 1942.

Emplacement in Fw-190 A-8/R2. From letf to right, MG-151/20E, BSK 16 guncamera and MK-108

It meet a later RLM requirement for a new aircraft cannon that could knock down enemy bombers with the lowest expenditure of ammunition.

In the service position.

In short, the MK 108 was a blow-back operated, rear-seared, belt fed 30 mm cannon using electric ignition and was charged and triggered by simple compressed air. One drawback was that once installed, there was no method to adjust the gun's harmonization. One distinctive physical feature was the very short gun barrel, which gave the MK 108 a low muzzle velocity of 500-510 meters per second. The maximum rate of fire was 650 rounds per minute. The operating sequence for the MK 108 went like this:

An ammunition can fed the rounds to the gun by means of a disintegrating belt
Once the sear was released, the bolt went forward under the action of the two driving springs
A projection on the top of the bolt passed through the ring, thus extracting a round
This then forced the round into the chamber and fired the round while the heavy bolt was still moving forwards
The empty cartridge case reinserted itself in its link after firing
Ejection was achieved by means of pawls activated by camming grooves that were cut into the top of the bolt
Finally, the new round slipped into position and the sequence repeated

With adaptator to DB-605 engine (BF-109G)

An interesting feature was that neither the barrel or receiver moved in recoil, the entire force of firing was absorbed by the rearward movement of the bolt against the driving springs, which buffered against the recoil. No locking mechanism was needed, because by the time the fired round had overcome the inertia of the firing bolt, the round had left the barrel and the pressure had dropped.

The nose mounting in a BF-110G.

There were two main types of ammunition for the MK 108 to use, a 30 mm high-explosive self-destroying tracer ("M-Shell" or "Mine-Shell") and a 30 mm incendiary shell. The first type was designed to cause a maximum blast effect by combining a very thin shell casing with the maximum load of explosive. Tests carried out at Rechlin (where most of the Luftwaffe aircraft and weapons tests were done) showed that with a "M-Shell" with 85 grains of explosive, five hits could destroy a B-17 or B-24 bomber. The second type of shell, the incendiary, was meant to be targeted at the fuel tanks of the enemy plane. Since some penetrating force was still needed to overcome the armor or airframe of the target, and not have the shell break up or explode upon contact, a hydrodynamic fuse was fitted so that the shell only exploded once it came into contact with liquid.

"Schräge Musik" emplacement BF-110G

There were two main types of ammunition for the MK 108 to use, a 30 mm high-explosive self-destroying tracer ("M-Shell" or "Mine-Shell") and a 30 mm incendiary shell. The first type was designed to cause a maximum blast effect by combining a very thin shell casing with the maximum load of explosive. Tests carried out at Rechlin (where most of the Luftwaffe aircraft and weapons tests were done) showed that with a "M-Shell" with 85 grains of explosive, five hits could destroy a B-17 or B-24 bomber. The second type of shell, the incendiary, was meant to be targeted at the fuel tanks of the enemy plane. Since some penetrating force was still needed to overcome the armor or airframe of the target, and not have the shell break up or explode upon contact, a hydrodynamic fuse was fitted so that the shell only exploded once it came into contact with liquid.

The total lengt of the MK-108 was 1060mm and his weight 63 kg.

Massive 6 x MK108 30mm in the Me-262A-1a/U5 fighter nose.

 

[Erich]

according to German documentation in my possession it was 3-4 hits from Minengeschoss properly placed at the wing-root and inboard engine of a US heavy to knock it down..........and it did. MK 108 was only used experimentally in the Bf 110G-4 NF and was not at all standard equipment.

First useage (Sturm FW type) was in Fw 190A-6/MK later in the low numbered variant A-7/MK in JG 1 and JG 11 then follow up in Sturmstaffel 1 in late 1943 and then of course we know about the success in the 3 SturmFw units in 44-45, also in the fall of 44 with JG 301.

 

[CharlesBronson]

MK 108 was only used experimentally in the Bf 110G-4 NF and was not at all standard equipment.

You are refering to the Schräge musik emplacement right ? because I saw several Messers with the twin MK nose mounting.

 

[net_sailor]

Hello!
I found a cutaway of the Do 335 with MK 103 enginie installation (right lower corner):

There is another version shown, with additional wing cannon for B variant.

[Edit]
Another view of MK 103M. The cannon is described as "MK 103 mot" i.e. for engine mounting (pix taken from "Dornier Do 335 Pfeil" by Heinz Nowarra, Schiffer Military History):

 

[CharlesBronson]

Very nice drawing Thanks. 8)


30x91mm RB ammunition:

Looking closer to the ammo used by the MK 108 it resemble in a way the modern grenade launcher cartrigdes, and that was the intentions, to send the biggest amount of explosives in the small time possible, the muzzle speed wasnt a priority. All the cartrigdes were electrically primed.

Minengeschoss ausf A:

Basic HE ammo, 330 grams bullet carring no less than 85 grams of nitropenta explosive content, to make some comparative a standar stick grenade carry 115 grams of explosive. Impact nose fuse AZ 1587.

Minengeschoss ausf A m-Zerleger:

Like the earlier but with a self destruction device wich actuated after 3 seconds, green band on bullet.

3cm Brandgranate-patrone:

Filled with a incendiary bursting charge Ph Mg of 140 grams, 490 m/s initial speed

Minengeschoss Ausf C L-spur:

He-tracer improved, the ausf C ammo was a streamlined desing in order to achieve a more straight flying path. The ausf C carried a litle less explosive filling, about 72 grams. The base of the projectile allowed a traced element .The muzzle speed was 510 m/s.

Minengeschoss Ausf c glimmspur:

Same as above described, but a with a dimer, non smoke tracer for low light/ night shooting.



Minengeschoss Ausf c glimmspur M -zerleger:

Same as above but with self destruction, used for the Night fighters in Reichs defense

 

[CharlesBronson]

Bordkanone BK 3,7 , part I:

The bordkanone series in one comprised of land weapons adapted to aeronautical use.The luftwaffe favoured the 3,7 centimeters gun mostly for two purposes:

• To engage bombers outside the range of their defensive machineguns
• To destroy armor more efficiently than the MK 101/103.

The BK 3,7 used the long recoil system to operate, a hidropneumatic damper cilinder was used to absorb the heavy recoil in the gun mounting.
It was feeded by one or two clips of 6 rounds. The ciclic rate was 140-150 rpm.
The gun had an overall length of 3750mm and it weights 295 kg.


Use in attack aircrafts:

The first aircraft to use the BK were some Ju-88 sin the variant JU-88P-2, this a/c had a couple of 37mm cannons in a large underbelly pod, the aircraft was front tested in late 1942 and probed to be effective agaist armor and artillery emplacements but too vulnerable to russian Flak.

Ju-88P-2.

The first really succesful use was achieved when it was installed on Stukas, in march 1943 an special detachment named "Panzerjagdkommando Weiss" tested in Crimea the first Stuka G-1. This variant was fabricated from JU-87D-5 with the wings MG 17s deleted and the large weapon used instead.

The strong wing of the Stuka designed to withstand the bomb load and the heavy G forces in high angles dived recuperations was very satisfactory when coupled with the BK shock absorber. The Panzerjagdkommando Weiss entered in action inmediatly over the russian bridgehead of Kuban destroying tanks and attacking ships. The famous stuka ace Rudel claimed as many as 70 landing boats destroyed with his new G-1.

Armorer with a 6 round clip, note that is a clip already inserted in the loading plate.

Gun armonization in a Ju-87G-2. Quite loud.

Guncam showing the effects of this weapon on russian landing ships:


View: https://www.youtube.com/watch?v=cU6OK1zSxKg


In Hs-129:

The most proficient tank-killer of the luftwaffe was also equipped with this cannon, although in small number.
Some Hs-129B-2 were converted to use an single BK in large ventral bay, this was feeded with a 12 shots clip. This variant ws called Hs-129B-2 /Wa (waffenträger= weapon carrier)

The counterrecoil cilinder was mounted below the gun, in the same way as the Luftwaffe field AA gun. Is idle to mention that despite the reduction in power compared with the Ju-87 this emplacement had the advantage of an easier gun armonization.

Factory shots, the last section of the barrel is not in place:

Just 25-35 of this variant were ever used.

 

[Denniss]

Error in the Ju 87 section:
The Ju 87 G-1 was built from the D-3, maybe also from the D-1. The G-2 is based on the D-5 with the increased wingspan.

 

[CharlesBronson]

Everybody seems to be very aware of the errors in this Topic, but none had saw some achievement...interesting and a little provocative if you asking me.

 

[Micdrow]

Everybody seems to be very aware of the errors in this Topic, but none had saw some achievement...interesting and a little provocative if you asking me.

I know how that can feel at times CharlesBronson, Keep up the good work. Heaven knows I made enough mistakes here.