Luftwaffe Cannons and Machineguns topic.

[lesofprimus]

Nice info...

 

[CharlesBronson]

Regarding the WB 81 Z manual, there are 500 rds. per gun

All right thanks for the correction, the WB was a nasty mean looking device.


Some examples of the ammo for MG-FF/M.

The mine explosive ammo, 92 grams shell, v0=675 m/s.

Armor piercing, 117 grams v==585 m/s.

Armor piercing Incendiary, phosphorous filling. 115 grams.

Armor piercing Incendiary, Elektron-thermit filling 117 grams, 575 m/s.

And the penetration table for the Panzergranate ammo:

 

[Joe2]

A single aircraft could wipe out a LOT of people if they where caught out in the open.

 

[CharlesBronson]

That was the idea.

The Mauser MG 151 family Part 1:

As early as 1934 the Mauser technicians began the development of a new airborne weapon to replace and/or complement the Oerlikons guns.
The MG 151 was designed in two different calibres at the same time, the heavy machinegun 15mm MG-151/15 and the MG 151/20 20 mm cannon. Interchangeability between both design was also provided.


MG 151/15.

The 15 mm heavy machinegun (incorrectly named cannon in some sources) was the first of the family to be introduced in service with the Me-109F2 in march 1941. The MG was operated by a short stroke recoil mechanism, both barrel and lock recoiled togheter and the the bolt is disingaged using a rotating bolts head.

Inner squematic.

The MG 151 used a large capacity bottlenecked case wich gave a high muzzle velocity, around 850-960 m/s. That provided a straigth flying path to target and improve the chances of hit. Due the generous muzzle speed the Ap bullet could defeat any aeronautical armor in that time, including the mitic "ironclad" ilyushin Il-2 Sturmovik. The overall lenght of the gun was 1917 mm, width 190mm, weight 42,5 kg and it shoot at some 700 rpm.

Loading a 125 rounds belt in a Hs-129B-1.

Triple mounting of MG 151 /15 in He-280.

Between 1944 and 1945 a lot of surplus MG-151/15 were used as a drilling (triple) in the Sd.Kfz 251 half-track.

 

[Eighthaf]

Two questions:

First; did FW-190s use underwing cannons in the Jagdbomber role?

Second; If the answer to the the first is 'yes', was there more than one sort?

I have a reference which shows two underwing gondola arrangements for -190s. One of them is probably for F-model birds, but I'm not sure about the other, which shows two pods, each with two 20mm cannon.

Thanks,

Eighth

 

[net_sailor]

The WB 151 dual cannon pack was used operationaly by JG 11 (there is known FW 190 A5/U12 Wnr. 410266, flown by Leutnant Erich Hondt, 2./JG 11 in Husum Oktober 1943)

 

[Denniss]

Weren't these cannon packs only used in the anti-bomber role ?

 

[CharlesBronson]

did FW-190s use underwing cannons in the Jagdbomber role?

It did not, generally the external gun was deleted.

The WB 151 dual cannon pack was used operationaly by JG 11 (there is known FW 190 A5/U12 Wnr. 410266, flown by Leutnant Erich Hondt, 2./JG 11 in Husum Oktober 1943)

A profile of this:

Weren't these cannon packs only used in the anti-bomber role ?

It does.

 

[RATHED]

Regarding tail fixed Mg 17s: I remember seeing a wartime manual designed to help allied crews recognized enemy planes, and in it a drawing of a he-111, showing weak spots, fuel tanks, defensive guns, etc. Well it also said that some he-111 carried a "remote controlled" MG on their tail. Well , we know they were fixed, but what that tells us it that at least allied pilots were worried about this defensive weapon, maybe even more then they should. It seems that that the tail gun did served the "scary" purpose, even if it did not downed many ( or any) enemies.

 

[CharlesBronson]

The gun should cover a point in wich none of the other MG can reach, that is the zero degrees astern, teorically when fired the attacking fighter manouver in order to evade being hit and then get in the arc of fire of the other defensive MGs.

 

[Erich]

a friend of the familie a Leutnant Hans Pancrius flew an Fw 190A-5/U12 and was an ace with 10 US heavy bombers to his credit while in 2./JG 11. He followed the US bomber stream out over the North Sea, shot one down and was never seen again. His sister still resides in Germany to this day

 

[Eighthaf]

Great, thanks gents. I presume then that the twin-cannon pack was indeed used against bombers then.

Anyone know which units?


Eighth

 

[Erich]

yes it was exclusively.... the A-5/U12 was in I./JG 11 only. from July 43 through December 1943. Replaced by the 190A-6

 

[CharlesBronson]

Mauser family Part 2, MG 151/20:

Despite the good characteristics in the 15 mm MG the german Air Force promptly favored the 20 mm gun. The air-to-air doctrine was turn to believe that is more likely to destroy an aircraft with high explosive shells and not just putting holes on it with AP ammunition.

The 20 mm diameter was always considerer as the minimum practical explosive shell. The MG 151 was designed to accept all the family of the FF, including the high capacity Minen bullet.

The first prototype MG 151/20 was put in a Do-17e used by the legion Kondor in Spain in 1937, the aircraft did not have a long career being shoot down by the republican AAA near Asturias.

There was some limitations to employ the same receiver and bolt of the 15 mm variant , the cartridge case had to be reduced in length, that and the heavier projectile gave as result a 100 m/s reduction in muzzle velocity compared with the 151/15. A shorter stroke in the bolts travel was however good for the rate of fire , about 780-800 rpm. It can handle bullets between 92 and 120 grams.

Mauser began the high scale production in 1941 and it was adopted first by the Bf-109F-4 in mid-1941. The MG 151 quickly replaced (or at list it was intended so) the older MG-FF in several types of aircraft. There was a remote triggered variant for fixed mounting and other manually charged for flexible defensive laffettes. As usual the cannon was feed by a disintegrable metallic belt and air cooled. The cannon weights 42 kg, and it had a overall length of 1620 mm

Flexible MG-151/20

It will be superfluous to describe all the aircraft wich employs this gun, some like the Me-109, Fw-190, Me-110G, Ju-88C, Ju-88G, Ju-87D, Me-210/ Me-410, He-177, FW-200, etc. It enough to say the it became the most used cannon trough the war.

Gun layout in a Me-210.

Double nose mounting in night fighter Me-110G-4, note the large flash hidders.

Compared with the allied guns like the Hispano Mk-II the Mauser 20 mm was alittle less powerful, it had in his favor a much superior reliability and rate of fire. In the MG-151 the german pilot could be sure that in the 99,99% times he pulls the trigger the Mauser went off…thing that cannot be reproduced in the French-British cannon.

Container WB 151 below Me-109G-4/R6.

MG 151/20 with open sights.

 

[Erich]

CB your last pic may well have been from NJG 5 archiv's. NJG 5 pilots with the Bf 110G-4's had probs with upper nose mounted Mk 108's jamming plus the hideous blinding flashes, which is quite funny as NJG 1 seems to not have had the prob being the leading NJG to wars end.

the Flash hiders were also used on the short barreled Mk 108 3cm's late war in such units as IV./NJG 6 which had a mix of Bf 110G-4's and Ju 88G-6's via photo evidence

E `

 

[CharlesBronson]

Probably, I take it from a old "Profile" series book. I had undestand tha Schnaufer hated the MK 108 because his blinding muzzle flash. I think he used an underbelly pod with twin Mausers in his BF-110.

 

[Tony Williams]

Mauser family Part 2, MG 151/20:

A couple of corrections:

There was some limitations to employ the same receiver and bolt of the 15 mm variant , the cartridge case had to be reduced in length, that and the heavier projectile gave as result a 100 m/s reduction in muzzle velocity compared with the 151/15. A shorter stroke in the bolts travel was however good for the rate of fire , about 780-800 rpm. It can handle bullets between 92 and 120 grams.

The cartridge overall length, the bolt stroke and the rate of fire (700-750 rpm) remained the same in the 15mm and 20mm versions. The reason that the cartridge case was shortened was that the 20mm projectiles were longer than the 15mm, so the case had to be shorter to keep the cartridges the same overall length. In the photo below (form the article on WW2 aircraft gun armament on my website) you can compare withe 15x96 of the MG 151 with the 20x82 of the MG 151/20.

Motorkanone MG 151/20 in B-109F.

Not so, as you can see the three gun barrels are the same (all are 7.92mm MG 17s). This pic is of any early model, before the 109E.

Incidentally, the reliability rate of the Hispano in 1944 was 99.93% (one failure every 1,500 rounds).

 

[Erich]

CB: Schnaufer used the underbelly destroyer pod only briefly and his mounts had the standard upper 3cm weapons, in fact his last bird only had the upper 3cm fitted but had the FuG 218 Neptun installed when he went over to Stab NJG 4.

NJG 4 crews had the Ju 88G-6 and must have thought why the CO of the NJG was not up to top equipment in 1945 as the Bf 110G-4 was almost completely outdated by then.......

 

[CharlesBronson]

The cartridge overall length, the bolt stroke and the rate of fire (700-750 rpm) remained the same in the 15mm and 20mm versions. The reason that the cartridge case was shortened was that the 20mm projectiles were longer than the 15mm, so the case had to be shorter to keep the cartridges the same overall length.

Thanks for your corrections but note I wrote the cartridge case had to be reduced in length and not the cartrigde itself.

In the photo below (form the article on WW2 aircraft gun armament on my website) you can compare withe 15x96 of the MG 151 with the 20x82 of the MG 151/20.

I am familiar with your website, there is no need to put a link to that in every post of yours.

CB: Schnaufer used the underbelly destroyer pod only briefly and his mounts had the standard upper 3cm weapons, in fact his last bird only had the upper 3cm fitted but had the FuG 218 Neptun installed when he went over to Stab NJG 4.

Thats funny, I tough he used the 30mm cannons but only briefly because the recoil/flash inconveniences for night fighting.

 

[Tony Williams]

Thanks for your corrections but note I wrote the cartridge case had to be reduced in length and not the cartrigde itself.

You also referred to "the shorter stroke in the bolt's travel" which would olnly be possible with a shorter cartridge: the bolt stroke length is directly linked to the overall cartridge length.

I am familiar with your website, there is no need to put a link to that in every post of yours.

But others may not be...