Luftwaffe Cannons and Machineguns topic.

[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.


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:

YouTube - WW2 Rudel STUKA JU87 (D-3) G-1 BEST RARE GUNCAM FOOTAGE


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]

Originally Posted by 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.

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

[CharlesBronson]

Thanks very much Micdrow, in fact is not about the errors, is about the attitude of some members who are allwiseknow, but I dont see those consuming a lot time to opening any important topic of any kind.

[Micdrow]

Well if you ever need a weapons subject to research, Ive always been interested in the rocket's hung underneth the P-51's and P-47'd during WWII. Love to read on what you can come up with the subject. Just never seem to have the time to due it myself.

[Tony Williams]

Originally Posted by Micdrow

Well if you ever need a weapons subject to research, Ive always been interested in the rocket's hung underneth the P-51's and P-47'd during WWII.

Here is an extract from Flying Guns – World War 2: Development of Aircraft Guns, Ammunition and Installations 1933-45:

The two RPs used by the USAAF had different histories. The 4.5" version originated from a 1940 request from the Ordnance Department to the National Defense Research Committee for help in developing a rocket primarily for use in aircraft. The availability of British research speeded the task so the first prototype was tested at the end of 1941. Somewhat bizarrely, the calibre of 4.5" (114 mm) was determined broadly by the specified warhead size and 330 m/s velocity, but specifically by the availability of surplus fire extinguisher tubes of that size! Unlike the British RPs, the 4.5" (designated the M8) had folding fins as they were launched from tubes. After significant problems with propellant quality, the M8 entered service in December 1943. In service, the tube-launching was found unnecessary and imposed drag penalties, so first the zero-length launcher from the USN's 5" (127 mm) HVAR (high velocity aircraft rocket) was utilised, then the HVAR itself was adopted, although the M8 remained in service alongside. The M8 weighed 18 kg and the warhead carried 2.3 kg of HE and reached 260 m/s. The HVAR, which achieved 390 m/s, weighed 63 kg and carried 3.5 kg of HE.

and as a bonus, the British RPs:

It is worth commenting on these RPs. The origin of the British ones lay in the 3" (76 mm) UP (unrotated projectile) unguided AA rockets, which were designed to be fired in salvoes. They were fitted to warships early in the war but replaced as more AA guns became available. After noting the Soviet experience with rockets fired from aircraft, the British adapted the UPs for this purpose and two different warheads were eventually devised; a 25 lb (11.3 kg) solid AP head, intended for use against armoured targets, and a 60 lb (27 kg) HE head for use against ships. Typical striking velocities were 460 m/s and 350 m/s respectively. Battle experience soon reversed this preference, however. The AP proved to be very effective against ships and surfaced submarines, because on hitting the sea the trajectory would flatten out and it would skim just under the surface for some distance, hitting with enough force to penetrate hulls and boilers. On the other hand, it was found that a hit from the AP did not necessarily cause fatal damage to a tank (it had particular difficulty in penetrating Tiger tanks), whereas the HE would devastate anything it struck – armoured or not – and was therefore a good general-purpose ground attack weapon.

and...

In contrast, one direct hit with a bomb or 60 lb RP meant certain destruction for the heaviest tank. However, their accuracy left a lot to be desired. Even under practice conditions, the hit rate for the RPs against tanks was no better than 5%. This was graphically illustrated by a demonstration put on by Typhoons against a captured Panther tank placed in the middle of an open field, helpfully painted white with large red crosses on it to make sure the pilots could see it. Of the 64 RPs fired (launched in a typical steep dive at ranges of 750-900 m), only three hit the tank. In battle, RP accuracy was considerably worse than this, with the official British calculation of hit probability against a single tank being 0.5% (in other words, 200 RPs had to be fired for each hit). Furthermore, some 20 – 30% of RP warheads failed to explode.

This fall in accuracy experienced in action may be attributed to the curious trajectory of the RP, which first dropped below the line of sight and then accelerated as the rocket motor took effect before it dropped again. Because of this it was generally desirable to fire them at a range of between 900-1,800 m. They were also very susceptible to side winds, with a mere 15 km/h wind being enough to miss the aiming mark by nearly 5 m, and the aircraft had to be absolutely steady at the instant of launching. This meant that a pilot needed a very cool and calculating head to ensure reasonable accuracy, something that was difficult to achieve in the heat of battle. It is worth noting that high-velocity cannon did not suffer from this problem, so would have experienced a much less significant fall-off in accuracy under combat conditions. RP accuracy was helped to some extent late in 1944 by the introduction of the modified Mk.IID gyro sight with calibrations suited to the RP. This presumably accounted in part for a measured improvement in the average RP miss distance between 1944 and 1945, from 57 m to just under 40 m.

The greatest accuracy was achieved in a near-vertical dive as this minimised the trajectory quirks, but this left the Typhoon visible to the usually accurate light FlaK, so many pilots preferred to attack at tree-top height, firing at distances as close as 500 m. This is curious given that theoretical British studies of different attack angles concluded that a low level (less than 30 m altitude) attack was eight times as dangerous in terms of exposure to AAA as a sixty-degree dive, but it is possible that a very low approach, using terrain, trees and buildings to mask the view of the AA gunners, might have had advantages.

[Micdrow]

Wow, Thanks Tony never expected such a quick response.

Again many thanks

[RATHED]

Originally Posted by 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.

Well, if it is apreciation you are looking for, I have to say that is by far the most interisting topic on the forum, at least to me. If anything, I would ask you to post more often...

Thanks!